bHLH-PAS proteins, genes thereof and utilization of the same

ABSTRACT

The present invention relates to proteins, including a protein represented by any of SEQ ID NOs: 1 to 3; a protein exhibiting an amino acid identity of 90% or more to the amino acid sequence represented by any of SEQ ID NOs: 1 to 3 and also having a transcription regulation ability; or a protein having a transcription regulation ability and containing an amino acid sequence encoded by a DNA which hybridizes under a stringent condition with a DNA consisting of the nucleotide sequence represented by the nucleotide numbers 102 to 2507 in the nucleotide sequence represented by SEQ ID NO: 4, 51 to 2456 in the nucleotide sequence represented by SEQ ID NO: 5, or 35 to 2440 in the nucleotide sequence represented by SEQ ID NO: 6, or a DNA encoding the same.

This is a 371 National Stage of PCT/JP01/11064 filed Dec. 17, 2001.

TECHNICAL FIELD

The present invention relates to a bHLH-PAS proteins, genes thereof and utilization of the same.

BACKGROUND ART

A protein having a basic helix-loop-helix (hereinafter referred to as bHLH) motif and a PAS domain (Per-Arnt-Sim homology domain) (such protein hereinafter being referred to as bHLH-PAS protein) binds to a DNA by forming a homodimer or a heterodimer to act as a transcription regulatory factor, whereby playing an important role in the transcriptional regulation of a gene involved in the cell proliferation, development and differentiation, as well as biological function exertion (Annu Rev Pharmacol Toxicol 2000; 40:519–61).

For example, an Ah receptor (aryl hydrocarbon receptor) is activated as a result of the binding of a ligand such as a dioxin to form a heterodimer with an Arnt (AhR nuclear translocator) which is also a bHLH-PAS protein, whereby binding to a transcription regulatory region for example of a drug metabolism enzyme gene, whose transcription is thus activated. An Hif activate the gene expression in a biological response under a hypoxic condition, while Per and Clock are involved in a circadian rhythm control and SRC-1 and TIF2 serve as coactivators of a steroidal hormone receptor family. Since a Sim involved in the development of the median line in a fruit fly is expressed in the median line during the development process also in a mammalian animal such as human, it is considered to be involved in the development of the latter, and a human Sim2 is suggested to be involved also in a genetic disease Down's syndrome (Genome Res 1997; 7:615–624, Chrast, R et al). In addition, NPAS1 and NPAS2 expressed mainly in the central nervous system in an adult are suggested to be involved in a mouse genetic disease exhibiting an abnormality in the nervous functions or behaviors (Proc. Natl. Acad. Sci. USA 1997; 94:713–18), and a knockout mouse whose NPAS 2 gene has been destroyed exhibited an abnormality in a long-term memory (Science 2000; 288:2226–2230).

Thus, a bHLH-PAS protein, in a tissue where it is expressed, is involved in the transcriptional regulation of a gene such as an enzyme gene or structural gene necessary for the development of the such a tissue as well as the exertion of the function, and its malfunction leads to a disease or disorder. Accordingly, in order to develop a means useful in the diagnosis, prophylaxis and therapy of such a disease or disorder, it is highly desirable to obtain a bHLH-PAS protein and a DNA encoding such a protein.

DISCLOSURE OF THE INVENTION

We made an effort under the circumstance described above and were successful finally in isolating a DNA encoding a bHLH-PAS protein which is expressed in a brain, whereby achieving the invention.

Thus, the present invention provides:

1) a DNA encoding any of the proteins (a) to (e):

(a) a protein comprising the amino acid sequence represented by any of SEQ ID NOs:1 to 3,

(b) a protein comprising an amino acid sequence exhibiting an amino acid identity of 90% or more to the amino acid sequence represented by any of SEQ ID NOs:1 to 3 and also having a transcription regulation ability,

(c) a protein comprising an amino acid sequence encoded by a DNA which hybridizes under a stringent condition with a DNA consisting of the nucleotide sequence represented by the nucleotide numbers 102 to 2507 in the nucleotide sequence represented by SEQ ID NO:4 and also having a transcription regulation ability, (d) a protein comprising an amino acid sequence encoded by a DNA which hybridizes under a stringent condition with a DNA consisting of the nucleotide sequence represented by the nucleotide numbers 51 to 2456 in the nucleotide sequence represented by SEQ ID NO:5 and also having a transcription regulation ability, and (e) a protein comprising an amino acid sequence encoded by a DNA which hybridizes under a stringent condition with a DNA consisting of the nucleotide sequence represented by the nucleotide numbers 35 to 2440 in the nucleotide sequence represented by SEQ ID NO:6 and also having a transcription regulation ability; 2) a DNA comprising any of the nucleotide sequences (a) to (d): (a) the nucleotide sequence represented by the nucleotide numbers 102 to 2507 in the nucleotide sequence represented by SEQ ID NO:4, (b) the nucleotide sequence represented by the nucleotide numbers 51 to 2456 in the nucleotide sequence represented by SEQ ID NO:5, (c) the nucleotide sequence represented by the nucleotide numbers 35 to 2440 in the nucleotide sequence represented by SEQ ID NO:6, and (d) the nucleotide sequence represented by the nucleotide numbers 1419 to 6164 in the nucleotide sequence represented by SEQ ID NO:54; 3) a vector containing the DNA according to the above-mentioned 1) or 2) (hereinafter referred to as an inventive vector); 4) a vector containing a DNA being formed by operably connecting a promoter to the upstream of the DNA according to the above-mentioned 1) or 2); 5) a method for producing a vector comprising integrating the DNA according to the above-mentioned 1) or 2) into a vector which can replicate itself in a host cell; 6) a transformant being formed by introducing the DNA according to the above-mentioned 1) or 2) or the vector according to the above-mentioned 3) into a host cell (hereinafter referred to as an inventive transformant); 7) a transformant according to the above-mentioned 6) wherein the host cell is an animal cell; 8) a transformant according to the above-mentioned 6) wherein the host cell is a E. coli or yeast; 9) a method for producing a transformant comprising introducing the DNA according to the above-mentioned 1) or 2) or the vector according to the above-mentioned 3) into a host cell; 10) a protein which is any of the following proteins (a) to (e) (hereinafter generally referred to as an inventive protein): (a) a protein comprising the amino acid sequence represented by any of SEQ ID NOs:1 to 3, (b) a protein comprising an amino acid sequence exhibiting an amino acid identity of 90% or more to the amino acid sequence represented by any of SEQ ID NOs:1 to 3 and also having a transcription regulation ability, (c) a protein comprising an amino acid sequence encoded by a DNA which hybridizes under a stringent condition with a DNA consisting of the nucleotide sequence represented by the nucleotide numbers 102 to 2507 in the nucleotide sequence represented by SEQ ID NO:4 and also having a transcription regulation ability, (d) a protein comprising an amino acid sequence encoded by a DNA which hybridizes under a stringent condition with a DNA consisting of the nucleotide sequence represented by the nucleotide numbers 51 to 2456 in the nucleotide sequence represented by SEQ ID NO:5 and also having a transcription regulation ability, and (e) a protein comprising an amino acid sequence encoded by a DNA which hybridizes under a stringent condition with a DNA consisting of the nucleotide sequence represented by the nucleotide numbers 35 to 2440 in the nucleotide sequence represented by SEQ ID NO:6 and also having a transcription regulation ability; 11) a method for producing an inventive protein comprising culturing a transformant being formed by introducing the DNA encoding any of the following proteins (a) to (e): (a) a protein comprising the amino acid sequence represented by any of SEQ ID NOs:1 to 3, (b) a protein comprising an amino acid sequence exhibiting an amino acid identity of 90% or more to the amino acid sequence represented by any of SEQ ID NOs:1 to 3 and also having a transcription regulation ability, (c) a protein comprising an amino acid sequence encoded by a DNA which hybridizes under a stringent condition with a DNA consisting of the nucleotide sequence represented by the nucleotide numbers 102 to 2507 in the nucleotide sequence represented by SEQ ID NO:4 and also having a transcription regulation ability, (d) a protein comprising an amino acid sequence encoded by a DNA which hybridizes under a stringent condition with a DNA consisting of the nucleotide sequence represented by the nucleotide numbers 51 to 2456 in the nucleotide sequence represented by SEQ ID NO:5 and also having a transcription regulation ability, and (e) a protein comprising an amino acid sequence encoded by a DNA which hybridizes under a stringent condition with a DNA consisting of the nucleotide sequence represented by the nucleotide numbers 35 to 2440 in the nucleotide sequence represented by SEQ ID NO:6 and also having a transcription regulation ability, into a host cell; 12) an antibody which recognizes an inventive protein or a polypeptide comprising a partial amino acid sequence thereof; 13) a method for detecting an inventive protein comprising: (1) a step for bringing an antibody which recognizes an inventive protein or a polypeptide comprising a partial amino acid sequence thereof into contact with a test sample, and, (2) a step for detecting a complex of a protein in the test sample and said antibody; 14) a method for screening for a substance which binds to an inventive protein comprising: (1) a step for bringing an inventive protein or a polypeptide comprising a partial amino acid sequence thereof into contact with a test sample, and, (2) a step for selecting a substance which binds to the inventive protein or said polypeptide; 15) a method for measuring a transcription regulation ability of an inventive protein or a polypeptide comprising a partial amino acid sequence thereof comprising a step for measuring the expression level of a reporter gene in a transformant being formed by introducing a gene i) and gene ii) into a host cell and in a transformant being formed by introducing a gene iii) and gene ii) and then comparing the measured expression levels, said genes being: i) a chimera gene being formed by connecting, to a downstream of a promoter which is capable of functioning in a host cell, a DNA encoding a fusion protein of a DNA binding region of a transcription regulatory factor which is capable of functioning in the host cell and an inventive protein or a polypeptide comprising a partial amino acid sequence thereof, ii) a reporter gene being formed by connecting a DNA encoding a reporter protein to a downstream of a promoter containing a DNA to which the DNA binding region described in i) can be bound and a minimum promoter which is capable of functioning in a host cell, iii) a gene being formed by connecting, in the downstream of the promoter described in i), a DNA encoding the DNA binding region described in i); 16) a method for screening for a substance which alters the transcription regulation ability of an inventive protein or a polypeptide comprising a partial amino acid sequence thereof comprising: (1) a step for bringing a transformant being formed by introducing: i) a chimera gene being formed by connecting, to a downstream of a promoter which is capable of functioning in a host cell, a DNA encoding a fusion protein of a DNA binding region of a transcription regulatory factor which is capable of functioning in the host cell and an inventive protein or a polypeptide comprising a partial amino acid sequence thereof, and, ii) a reporter gene being formed by connecting a DNA encoding a reporter protein to a downstream of a promoter containing a DNA to which the DNA binding region described in i) can be bound and a minimum promoter which is capable of functioning in a host cell, into a host cell into contact with a test substance and then measuring the expression level of said reporter gene in the presence of the test substance, and, (2) a step for selecting a test substance which results in a expression level of said reporter gene, as measured in the step (a), which is different substantially from the expression level of said reporter gene in the absence of the test substance; 17) a use of the DNA according to the above-mentioned 1 for a two-hybrid assay; 18) a method for screening for a substance which alters the intracellular expression level of an inventive protein or a polypeptide comprising a partial amino acid sequence thereof comprising: (1) a step for bringing a transformant being formed by introducing into a host cell a reporter gene obtained by ligating in a functional manner the expression regulation region of a DNA encoding said protein into contact with a test substance and then measuring the expression level of said reporter gene in the presence of the test substance, and, (2) a step for selecting a test substance which results in a expression level of said reporter gene, as measured in the step (1), which is different substantially from the expression level of said reporter gene in the absence of the test substance; 19) a polynucleotide consisting of 10 to 5000 nucleotides capable of hybridizing under a stringent condition with a polynucleotide consisting of the nucleotide sequence represented by SEQ ID NO:4, 5, 6 or 54 or the nucleotide sequence complementary to said nucleotide sequence; 20) a polynucleotide consisting of 10 to 5000 nucleotides comprising a partial nucleotide sequence of the nucleotide sequence represented by SEQ ID NO:4, 5, 6 or 54 or the nucleotide sequence complementary to said partial nucleotide sequence; 21) a method for detecting a nucleic acid encoding an inventive protein comprising: (1) a step for bringing a polynucleotide consisting of 10 to 5000 nucleotides capable of hybridizing under a stringent condition with a polynucleotide consisting of the nucleotide sequence represented by SEQ ID NO:4, 5, 6 or 54 or the nucleotide sequence complementary to said nucleotide sequence into contact with a nucleic acid derived from a test sample under a hybridization condition, and, (2) a step for detecting a hybrid of said polynucleotide and the nucleic acid derived from the test sample; 22) a polynucleotide consisting of 10 to 50 nucleotides capable of being annealed under a polymerase chain reaction condition with a polynucleotide consisting of the nucleotide sequence represented by SEQ ID NO:4, 5, 6 or 54 or the nucleotide sequence complementary to said nucleotide sequence; 23) a polynucleotide consisting of 10 to 50 nucleotides comprising a partial nucleotide sequence of the nucleotide sequence represented by SEQ ID NO:4, 5, 6 or 54 or the nucleotide sequence complementary to said partial nucleotide sequence; 24) a polynucleotide consisting of 10 to 50 nucleotides capable of being annealed under a polymerase chain reaction condition with a polynucleotide consisting of the nucleotide sequence represented by any of SEQ ID NOs:43 to 51 or the nucleotide sequence complementary to said nucleotide sequence; 25) a polynucleotide consisting of 10 to 50 nucleotides comprising a partial nucleotide sequence of the nucleotide sequence represented by any of SEQ ID NOs:43 to 51 or the nucleotide sequence complementary to said partial nucleotide sequence; 26) a polynucleotide comprising the nucleotide sequence represented by any of SEQ ID NOs:11 to 42; 27) a kit comprising one or more polynucleotides selected from the following polynucleotides (a) to (f) (hereinafter sometimes referred to as an inventive kit): (a) a polynucleotide consisting of 10 to 5000 nucleotides capable of hybridizing under a stringent condition with a polynucleotide consisting of the nucleotide sequence represented by SEQ ID NO:4, 5, 6 or 54 or the nucleotide sequence complementary to said nucleotide sequence, (b) a polynucleotide consisting of 10 to 50 nucleotides capable of being annealed under a polymerase chain reaction condition with a polynucleotide consisting of the nucleotide sequence represented by SEQ ID NO:4, 5, 6 or 54 or the nucleotide sequence complementary to said nucleotide sequence, (c) a polynucleotide consisting of 10 to 5000 nucleotides comprising a partial nucleotide sequence of the nucleotide sequence represented by SEQ ID NO:4, 5, 6 or 54 or the nucleotide sequence complementary to said partial nucleotide sequence, (d) a polynucleotide consisting of 10 to 50 nucleotides capable of being annealed under a polymerase chain reaction condition with a polynucleotide consisting of the nucleotide sequence represented by any of SEQ ID NOs:43 to 51 or the nucleotide sequence complementary to said nucleotide sequence, (e) a polynucleotide consisting of 10 to 50 nucleotides comprising a partial nucleotide sequence of the nucleotide sequence represented by any of SEQ ID NOs:43 to 51 or the nucleotide sequence complementary to said partial nucleotide sequence, and (f) a polynucleotide comprising the nucleotide sequence represented by any of SEQ ID NOs:11 to 42; 28) a method for amplifying a genomic DNA encoding an inventive protein comprising a step for conducting a polymerase chain reaction using one or more polynucleotides selected from polynucleotides (f) to (j) as primers together with the genomic DNA as a template, said polynucleotides being: (f) a polynucleotide consisting of 10 to 50 nucleotides capable of being annealed under a polymerase chain reaction condition with a polynucleotide consisting of the nucleotide sequence represented by SEQ ID NO:4, 5, 6 or 54 or the nucleotide sequence complementary to said nucleotide sequence, (g) a polynucleotide consisting of 10 to 50 nucleotides comprising a partial nucleotide sequence of the nucleotide sequence represented by SEQ ID NO:4, 5, 6 or 54 or the nucleotide sequence complementary to said partial nucleotide sequence, (h) a polynucleotide consisting of 10 to 50 nucleotides capable of being annealed under a polymerase chain reaction condition with a polynucleotide consisting of the nucleotide sequence represented by any of SEQ ID NOs:43 to 51 or the nucleotide sequence complementary to said nucleotide sequence, (i) a polynucleotide consisting of 10 to 50 nucleotides comprising a partial nucleotide sequence of the nucleotide sequence represented by any of SEQ ID NOs:43 to 51 or the nucleotide sequence complementary to said partial nucleotide sequence, and (j) a polynucleotide comprising the nucleotide sequence represented by any of SEQ ID NOs:11 to 42; 29) a method for amplifying a cDNA encoding an inventive protein comprising a step for conducting a polymerase chain reaction using one or more polynucleotides selected from polynucleotide (f) or (g) as primers together with the cDNA as a template, said polynucleotides being: (f) a polynucleotide consisting of 10 to 50 nucleotides capable of being annealed under a polymerase chain reaction condition with a polynucleotide consisting of the nucleotide sequence represented by any of SEQ ID NOs:4 to 6 or the nucleotide sequence complementary to said nucleotide sequence, and (g) a polynucleotide consisting of 10 to 50 nucleotides comprising a partial nucleotide sequence of the nucleotide sequence represented by any of SEQ ID NOs:4 to 6 or the nucleotide sequence complementary to said partial nucleotide sequence; 30) a method for analyzing a genotype of a gene encoding an inventive protein comprising a step for investigating whether a nucleotide sequence encoding the inventive protein, in a nucleic acid in a test sample, contains a nucleotide sequence encoding an amino acid sequence which is different from the amino acid sequence of a standard protein or not; 31) a method according to the above-mentioned 30) wherein the step for investigating whether a nucleotide sequence encoding the amino acid sequence which is different from the amino acid sequence of a standard protein is contained or not comprises a step for amplifying a DNA encoding an inventive protein using the nucleic acid in the test sample as a template and then determining the nucleotide sequence of the amplified DNA; 32) a method according to the above-mentioned 30) wherein the step for investigating whether a nucleotide sequence encoding the amino acid sequence which is different from the amino acid sequence of a standard protein is contained or not comprises a step for amplifying a DNA encoding the amino acid sequence of an inventive protein using the nucleic acid in the test sample as a template and then subjecting the amplified DNA to an electrophoresis to measure the mobility; 33) a method according to the above-mentioned 30) wherein the step for investigating whether a nucleotide sequence encoding the amino acid sequence which is different from the amino acid sequence of a standard protein is contained or not comprises a step for investigating the pattern of a hybridization under a stringent condition between the nucleic acid of a test sample or an amplification product of said nucleic acid and a polynucleotide consisting of 10 to 5000 nucleotides capable of hybridizing under a stringent condition with a polynucleotide consisting of the nucleotide sequence represented by SEQ ID NO:4, 5, 6 or 54 or the nucleotide sequence complementary to said nucleotide sequence; 34) a method according to any of the above-mentioned 30) to 33) wherein the amino acid sequence of the standard protein is the amino acid sequence represented by SEQ ID NO:1, 2 or 3; 35) a method for promoting the expression of a drebrin 1 in a mammalian cell comprising a step for providing the mammalian cell with the DNA according to the above-mentioned 1 or 2 in a position enabling the expression of said DNA in said cell (hereinafter sometimes referred to as an inventive expression promoting method); 36) a method according to the above-mentioned 35 wherein said mammalian cell is a cell present in a body of a mammalian animal which can be diagnosed to suffer from a disease accompanied with a mental retardation or from Alzheimer's disease; 37) a gene therapy agent comprising the DNA according to the above-mentioned 1 or 2 as an active ingredient and obtained by formulating said active ingredient in a pharmaceutically acceptable carrier.

BRIEF DESCRIPTIONS OF THE DRAWINGS

FIG. 1 shows the results of the one hybrid assay using pGL3-TATA-Galx4 which is a reporter gene plasmid for verifying the transcription regulation ability of an inventive protein. The abscissa represents the tested transformants (the right side is a transformant which expresses a Gal4 DNA binding region exclusively and corresponds to a control, while the left side is a transformant which expresses a fusion protein formed by binding a Gal4 DNA binding region to an inventive protein transcrptional regulation region). The ordinate represents the measured values of the luciferase activity (i.e., the expression levels of the reporter gene), each of which is an index of the transcription regulation ability of a transcription regulatory factor.

FIG. 2 shows the results of a reporter gene assay for verifying the promoter activity possessed by the expression regulation region of a DNA encoding an inventive protein. The abscissa represents the tested expression regulation region. Starting from the left end, the bars represents the inventive protein-encoding DNA expression regulation regions containing the regions from the inventive protein gene transcription initiation point to the upstream by about 1 kbp, 2.5 kbp and 5 kbp (in the figure, designated as −5 kbp NXF genome, −2.5 kbp NXF genome and −1 kbp NXF genome) and a herpes simplex virus thymidine kinase promoter (HSV-TK enhancer) as a control. The ordinate represents the measured values of the luciferase activity (i.e., the expression levels of the reporter gene), each of which is an index of the promoter activity possessed by the expression regulation region of a protein gene.

BEST MODE FOR CARRYING OUT THE INVENTION

The invention is further detailed below.

An inventive protein includes a protein comprising the amino acid sequence represented by any of SEQ ID NOs:1 to 3 (wherein the transcription regulatory factor comprising the amino acid sequence represented by SEQ ID NO:1 is a human-derived inventive transcription regulatory factor, which may sometimes be designated as hNXF; the transcription regulatory factor comprising the amino acid sequence represented by SEQ ID NO:2 is a mouse-derived inventive transcription regulatory factor, which may sometimes be designated as mNXF; the transcription regulatory factor comprising the amino acid sequence represented by SEQ ID NO:3 is a rat-derived inventive transcription regulatory factor, which may sometimes be designated as rNXF), a protein comprising an amino acid sequence exhibiting an amino acid identity of 90% or more to the amino acid sequence represented by any of SEQ ID NOs:1 to 3 and also having a transcription regulation ability, a protein comprising an amino acid sequence encoded by a DNA which hybridizes under a stringent condition with a DNA consisting of the nucleotide sequence represented by the nucleotide numbers 102 to 2507 in the nucleotide sequence represented by SEQ ID NO:4 and also having a transcription regulation ability, a protein comprising an amino acid sequence encoded by a DNA which hybridizes under a stringent condition with a DNA consisting of the nucleotide sequence represented by the nucleotide numbers 51 to 2456 in the nucleotide sequence represented by SEQ ID NO:5 and also having a transcription regulation ability and a protein comprising an amino acid sequence encoded by a DNA which hybridizes under a stringent condition with a DNA consisting of the nucleotide sequence represented by the nucleotide numbers 35 to 2440 in the nucleotide sequence represented by SEQ ID NO:6 and also having a transcription regulation ability.

The difference from the amino acid sequence represented by any of SEQ ID NOs:1 to 3 observed in the amino acid sequence of an inventive protein may for example be a variation such as the deletion, substitution, modification and addition of amino acids. Such a variation includes a variation which can artificially be introduced by means of a site-directed mutagenesis method or a mutagenic treatment as well as a polymorphic variation which occurs naturally such as a difference in an amino acid sequence resulting from the difference by the animal line, individual, organ and tissue.

In the invention, the “amino acid identity” means an identity and a homology in the amino acid sequence between two proteins. The “amino acid identity” described above can be determined by comparing two amino acid sequence which are aligned optimally over the entire range of a reference amino acid. A reference protein here may have an addition or deletion (for example, a gap) in the optimal alignment of the two amino acid sequences. Such an amino acid identity can be calculated for example by producing an alignment utilizing a Clustal W algorism [Nucleic Acid Res., 22 (22): 4673–4680 (1994)] using a Vector NTI. The amino acid identity can be investigated also by using a sequence analysis software, typically Vector NTI, GENETYX-MAC or any other analytical tools provide DNA public database.

A preferred amino acid identity in the invention may for example be 90% or higher.

A “DNA which hybridizes under a stringent condition” described above may for example be a DNA capable of maintaining a hybrid, which was formed previously as a DNA-DNA hybrid by a hybridization at 65° C. at a high ion concentration [for example using 6×SSC (900 mM sodium chloride, 90 mM sodium citrate)], even after washing for 30 minutes at 65° C. at a low ion concentration [for example using 0.1×SSC (15 mM sodium chloride, 1.5 mM sodium citrate)]. The transcription regulation ability of an inventive protein can be evaluated based for example on an assay using a reporter gene described below.

A DNA encoding an inventive protein (hereinafter referred to as an inventive DNA) can be obtained in accordance with a genetic engineering method described in J. Sambrook, E. F. Frisch, T. Maniatis, Molecular Cloning, 2nd Edition, Cold Spring Harbor Laboratory, 1989, from a tissue of an animal such as human, mouse, rat and the like.

Typically, a total RNA derived from a tissue of an animal such as human, mouse and rat is first prepared. For example, a brain tissue is pulverized in a solution containing a protein denaturant such as guanidine hydrochloride or guanidine thiocyanate, and then the pulverized material is treated with phenol, chloroform and the like, to denature the protein. The denatured protein is removed for example by a centrifugation to obtain a supernatant, from which the total RNA is extracted by a guanidine hydrochloride/phenol method, SDS-phenol method, guanidine thiocyanate/CsCl method and the like. A commercially available kit based on the methods described above may for example be ISOGEN (NIPPON GENE). The resultant total RNA is used as a template and an oligo dT primer is annealed to a poly A sequence of the RNA, whereby synthesizing a single-stranded cDNA using a reverse transcriptase. Then, the synthesized single-stranded cDNA is used as a template together with a primer which is an RNA obtained by inserting a nick and a gap into the RNA chain using an E. coli RnaseH, whereby synthesizing a double-stranded cDNA using an E. coli DNA polymerase I. Subsequently, the both ends of the synthesized double-stranded cDNA is made blunt using a T4 DNA polymerase. The double-stranded cDNA having both blunt ends is purified and recovered by means of a standard procedure such as a phenol-chloroform extraction and ethanol precipitation. A commercially available kit based on the methods described above may for example be a cDNA synthesis system plus (Amarsham Pharmacia Biotech) or a TimeSaver cDNA synthesis kit (Amarsham Pharmacia Biotech). Then the resultant double-stranded cDNA is ligated to a vector such as a plasmid pUC118 or phage λgt10 using a ligase to prepare a cDNA library. As such a cDNA library, a commercially available cDNA library (GIBCO-BPL or Clontech) may also be employed.

Alternatively, a genomic DNA may be prepared from a tissue sample of an animal such as human, mouse and rat in accordance with a standard method described for example in J. Sambrook, E. F. Frisch, T. Maniatis, Molecular Cloning, 2nd Edition, Cold Spring Harbor Laboratory (1989), or M. Muramatsu, “Labomanual genetic engineering” (Maruzen, 1988). For example, when the sample is a hair, 2 or 3 hairs are washed with a sterilized water and then with ethanol, cut into 2 to 3 mm pieces, which are combined with 200 μl of a BCL-Buffer [10 mM Tris-HCl (pH7.5), 5 mM MgCl₂, 0.32 sucrose, 1 Triton X-100] followed by a Proteinase K at the final concentration of 100 μl/ml and SDS at the final concentration of 0.5 (w/v). The mixture thus obtained is incubated at 70° C. for 1 hour, and then subjected to a phenol/chloroform extraction to obtain a genomic DNA. When the sample is a peripheral blood, the sample is treated using a DNA-Extraction kit (Stratagene) and the like to obtain a genomic DNA. The resultant genomic DNA is ligated to a vector such as a λgt10 using a ligase to obtain a genomic DNA library. As such a genomic DNA library, a commercially available genomic DNA library (Stratagene) may also be employed.

From a cDNA library or genomic DNA library obtained as described above, an inventive DNA can be obtained for example by a polymerase chain reaction (hereinafter abbreviated as PCR) using as a primer an oligonucleotide comprising a partial nucleotide sequence of the nucleotide sequence represented by SEQ ID NO:4, 5, 6 or 54 or the nucleotide sequence complementary to said partial nucleotide sequence or by a hybridization method using as a probe a DNA comprising the nucleotide sequence represented by SEQ ID NO:4, 5, 6 or 54 or a partial nucleotide sequence of said partial nucleotide sequence.

A primer employed in a PCR may for example be an oligonucleotide having a length of about 10 nucleotides to about 50 nucleotides which is an oligonucleotide comprising a nucleotide sequence selected from a 5′ non-translation region of the nucleotide sequence represented by SEQ ID NO:4, 5, 6 or 54 and which is an oligonucleotide comprising the nucleotide sequence complementary to a nucleotide sequence selected from a 3′ non-translation region of the nucleotide sequence represented by SEQ ID NO:4, 5, 6 or 54. Typically, the forward primer may for example be the oligonucleotide consisting of the nucleotide sequence represented by SEQ ID NO:7 and the oligonucleotide consisting of the nucleotide sequence represented by SEQ ID NO:8. The reverse primer may for example be the oligonucleotide consisting of the nucleotide sequence represented by SEQ ID NO:9 and the oligonucleotide consisting of the nucleotide sequence represented by SEQ ID NO:10. An example of the PCR condition involves an incubation in 50 μl of a reaction solution containing 5 μl of a 10-fold diluted buffer for a LA-Taq polymerase (Takara), 5 μl of a 2.5 mM dNTP mixture (each 2.5 mM dATP, dGTP, dCTP and dTTP) (the final concentration of each of dATP, dGTP, dCTP and dTTP is 0.25 mM), each 0.25 to 1.25 μl of 20 μM primers (final concentration of 0.1 to 0.5 μM), 0.1 to 0.5 μg of a template cDNA and 1.25 units of a LA-Taq polymerase (Takara) for 1 minutes at 95° C. followed by 3 minutes at 68° C. in a single cycle, the cycle being repeated 35 times.

A probe employed in a hybridization method may for example be the DNA consisting of the nucleotide sequence represented by the nucleotide numbers 102 to 2507 in the nucleotide sequence represented by SEQ ID NO:4, a DNA consisting of the nucleotide sequence represented by the nucleotide numbers 51 to 2456 in the nucleotide sequence represented by SEQ ID NO:5, a DNA consisting of the nucleotide sequence represented by the nucleotide numbers 35 to 2440 in the nucleotide sequence represented by SEQ ID NO:6, a DNA consisting of the nucleotide sequence represented by the nucleotide numbers 1419 to 6164 in the nucleotide sequence represented by SEQ ID NO:54 and the like. An example of the hybridization condition involves an incubation at 65° C. in the presence of 6×SSC (0.9M sodium chloride, 0.09M sodium citrate), 5× Denhart's solution (0.1 (w/v) ficoll 400, 0.1 (w/v) polyvinyl pyrrolidone), 0.1 (w/v) BSA), 0.5 (w/v) SDS and 100 μg/ml denatured salmon sperm DNA followed by an incubation at room temperature for 15 minutes in the presence of 1×SSC (0.15M sodium chloride, 0.015M sodium citrate) and 0.5 (w/v) SDS, followed by an incubation at 68° C. for 30 minutes in the presence of 0.1×SSC (0.015M sodium chloride, 0.0015M sodium citrate) and 0.5 (w/v) SDS. Alternatively, an incubation at 65° C. in the presence of 5×SSC, 50 mM HEPES, pH7.0, 10× Denhart's solution and 20 μg/ml denatured salmon sperm DNA followed by an incubation at room temperature for 30 minutes in 2×SSC, followed by an incubation at 65° C. for 40 minutes in 0.1×SSC, which is repeated twice, may also be exemplified.

An inventive DNA can be prepared also by performing a chemical synthesis of a nucleic acid in accordance with a standard method such as a phosphite triester method (Hunkapiller, M. et al., Nature, 310, 105, 1984) based on the nucleotide sequence represented by SEQ ID NO:4, 5, 6 or 54.

An inventive DNA thus obtained can be cloned into a vector in accordance with a genetic engineering method described in J. Sambrook, E. F. Frisch, T. Maniatis, Molecular Cloning, 2nd Edition, Cold Spring Harbor Laboratory (1989). Typically, the cloning can for example be performed using a TA cloning kit (Invitrogen) or a commercially available plasmid vector such as pBluescriptII (Stratagene).

The nucleotide sequence of a resultant inventive DNA can be identified by a Maxam Gilbert method (described for example in Maxam, A. M. & W. Glibert, Proc. Natl. Acad. Sci. USA, 74, 560, 1997) or a Sanger method (described for example in Sanger, F. & A. R. Coulson, J. Mol. Biol., 94, 441, 1975, Sanger, F. & Nicklen and A. R. Coulson., Proc. Natl. Acad. Sci. USA, 74, 5463, 1997).

A typical example of an inventive DNA may for example be the DNA consisting of the nucleotide sequence represented by the nucleotide numbers 102 to 2507 in the nucleotide sequence represented by SEQ ID NO:4, a DNA consisting of the nucleotide sequence represented by the nucleotide numbers 51 to 2456 in the nucleotide sequence represented by SEQ ID NO:5, a DNA consisting of the nucleotide sequence represented by the nucleotide numbers 35 to 2440 in the nucleotide sequence represented by SEQ ID NO:6, a DNA consisting of the nucleotide sequence represented by the nucleotide numbers 1419 to 6164 in the nucleotide sequence represented by SEQ ID NO:54 and the like.

An inventive DNA has an ability of promoting the expression of a drebrin 1 as evident from the Examples described below. In this context, the drebrin 1 is depleted in a cell of an Alzheimer's disease patient, and the suppression of it may contribute to the recovery from the cognition dysfunction and the memory insufficiency in the Alzheimer's disease. Accordingly, an inventive DNA is useful as an active ingredient in a gene therapy pharmaceutical.

An inventive vector can be constructed by integrating an inventive DNA, in accordance with a standard genetic engineering method, into a vector capable of being utilized in a host cell to which said gene is introduced (hereinafter referred to as a basic vector), such as a vector which contains a gene information capable of being replicated in the host cell, which can independently be proliferated, which can be isolated and purified from the host cell and which has a detectable marker.

A basic vector which can be employed for constructing an inventive vector may for example be a plasmid pUC119 (Takara) or phagimid pBluescriptII (Stratagene) when using a coliform as a host cell. When using a budding yeast as a host cell, then plasmids pGBT9, pGAD242, pACT2 (Clontech) may be exemplified. When using a mammalian cell as a host cell, a vector containing an autonomous replication origin derived from a virus such as pRc/RSV, pRc/CMV (Invitrogen), bovine papilloma virus plasmid pBV (Amarsham Pharmacia Biotech) or EB virus plasmid pCEP4 (Invitrogen) and a virus such as a vaccinia virus may be exemplified, while an insect virus such as a baculovirus may be exemplified when using a insect cell as a host cell.

In order to integrate an inventive DNA into a virus such as a baculovirus or vaccinia virus, a transfer vector containing a nucleotide sequence homologous to the genome of a virus to be employed can be used. Such a transfer vector is typically a plasmid available from Pharmingen such as pVL1372, pVL1393 (Smith, G. E., Summers M. E. et al., Mol. Cell Biol., 3, 2156–2165 (1983) and pSFB5 (Funahashi, S. et al., J. Virol., 65, 5584–5588 (1991). When an inventive DNA is inserted into a transfer vector described above and the transfer vector and the genome of a virus are introduced into a host cell simultaneously, a homologous recombination occurs between the transfer vector and the genome of the virus, whereby obtaining a virus into whose genome the inventive gene is integrated. The genome of a virus may be the genome for example of Baculovirus, Adenovirus, Vacciniavirus and the like.

More specifically, an inventive gene is integrated for example into a baculovirus by inserting the inventive DNA into a multiple cloning site of a transfer vector such as pVL1393 or pBL1392 followed by introducing the DNA of said transfer vector and a baculovirus genomic DNA (Baculogold; Pharmingen) into an insect cell line Sf21 (available from ATCC) for example by a calcium phosphate method followed by incubating the resulting cell. A virus particle containing the genome of the virus into which the inventive DNA has been inserted is recovered from the culture medium for example by a centrifugation, and then made free from proteins using phenol and the like, whereby obtaining the genome of the virus containing the inventive DNA. Subsequently, the genome of said virus is introduced into a host cell having a virus particle forming ability such as an insect cell line Sf21 for example by a calcium phosphate method and the resultant cell is incubated, whereby proliferating the virus particle containing the inventive DNA.

On the other hand, a relatively small genome such as that of a mouse leukemia retrovirus can directly be integrated with an inventive DNA without using any transfer vector. For example, a virus vector DC(X) (Eli Gilboa et al., BioTechniques, 4, 504–512 (1986)) is integrated with an inventive DNA on its cloning site. The resultant virus vector into which the inventive DNA has been integrated is introduced into a packaging cell such as an Ampli-GPE (J. Virol., 66, 3755 (1992)), whereby obtaining a virus particle containing the genome of the virus into which the inventive DNA has been inserted.

A promoter capable of functioning in a host cell is operably connected to the upstream of an inventive DNA and then integrated into a basic vector such as those described above, whereby constructing an inventive vector capable of allowing the inventive DNA to be expressed in the host cell. The expression “operably connected” means that a promoter and an inventive gene are bound to each other in a condition which allows the inventive DNA is expressed under the control of the promoter in a host cell into which the inventive DNA is to be introduced. A promoter capable of functioning in a host cell may for example be a DNA exhibiting a promoter activity in a host cell into which it is to be introduced. Those which may be exemplified when the host cell is a coliform cell are E. coli lactose operon promoter (lacP), tryptophan operon promoter (trpP), arginine operon promoter (argP), galactose operon promoter (galP), tac promoter, T7 promoter, T3 promoter, λ phage promoter (λ-pL, λ-pR) and the like, while those which may be exemplified when the host cell is an animal cell or fission yeast are Rous sarcoma virus (RSV) promoter, cytomegalovirus (CMV) promoter, simian virus (SV40) early or late promoter, mouse mammary tumor virus (MMTV) promoter and the like. Those which may be exemplified when the host cell is a budding yeast are an ADH1 promoter and the like (the ADH1 promoter can be prepared by a standard genetic engineering method for example from an yeast expression vector pAAH5 comprising an ADH1 promoter and terminator [available from Washington Research Foundation, Ammerer et al., Method in Enzymology, 101 part (p. 192–201)]; the ADH1 promoter is encompassed in the U.S. patent application Ser. No. 299,733 by Washington Research Foundation, and should be used industrially or commercially in United States only after obtaining the approval from the claimant).

When a basic vector which initially possesses a promoter capable of functioning in a host cell is employed, an inventive DNA may be inserted to the downstream of said promoter so that the vector-possessed promoter and the inventive DNA are operably connected to each other. For example, each of the plasmids such as pRc/RSV and pRc/CMV described above is provided with a cloning site downstream of a promoter capable of functioning in an animal cell, and by inserting an inventive DNA into said cloning site followed by a introduction into an animal cell, the inventive DNA can be expressed. Since any of these plasmids has previously been integrated with a SV40 autonomous replication origin, the introduction of said plasmid into a host cell which has been transformed with an SV40 genome from which an ori is deleted, such as a COS cell, leads to an extremely increased number of the intracellular plasmid copies, resulting in a high expression of the inventive DNA which has been integrated into said plasmid. Also since the plasmid pACT2 for yeast described above possesses an ADH1 promoter, an inventive vector capable of allowing an inventive DNA to be expressed highly in a budding yeast such as CG1945 (Clontech) can be constructed by inserting the inventive DNA into the downstream of the ADH1 promoter of said plasmid or a derivative thereof.

Furthermore, by binding an inventive DNA or a DNA comprising its partial nucleotide sequence and a DNA encoding other desired protein to each other with aligning their reading frames upstream of which a promoter capable of functioning in a host cell is then operably connected and then integrated into a basic vector described above, it is possible to construct an inventive vector capable of allowing a DNA encoding a fusion protein with said desired protein to be expressed in the host cell. Such a construction of an inventive vector may also employ a basic vector which originally possesses a promoter capable of functioning in a host cell and a DNA encoding a desired protein described above. When a DNA encoding a fusion protein of an inventive protein or a polypeptide comprising its partial amino acid sequence with a Gal4 DNA binding region is intended to be expressed, a pGBT9 or pAS2 (Clontech) when the host cell is a budding yeast and a pM vector (Clontech) when the host cell is an animal cell may for example be employed. When a DNA encoding a fusion protein of an inventive protein or a polypeptide comprising its partial amino acid sequence with a LexA DNA binding region is intended to be expressed, a pGilda vector for a budding yeast expression (Clontech) may for example be employed. When a DNA encoding a fusion protein of an inventive protein or a polypeptide comprising its partial amino acid sequence with a glutathion S transferase (hereinafter designated as GST) is intended to be expressed, a pGEX series for a coliform expression (Amersham Pharmacia) may for example be employed.

By introducing a constructed inventive vector into a host cell, an inventive transformant can be obtained. A method for introducing an inventive vector into a host cell may be a standard introducing method suitable for the host cell. For example, when E. coli is employed as a host cell, a standard method such as a calcium chloride method or electroporation described for example in J. Sambrook, E. F. Frisch, T. Maniatis, Molecular Cloning, 2nd Edition, Cold Spring Harbor Laboratory (1989) may be employed. When a mammalian cell or insect cell is employed as a host cell, the introduction into a cell described above can be effected in accordance with a general gene introduction method such as a calcium phosphate method, DEAE dextran method, electroporation, lipofection and the like. When an yeast is employed as a host cell, the introduction can be effected for example by means of an Yeast transformation kit (Clontech) based on a lithium method.

When a virus is employed as a vector, the genome of the virus can be introduced into a host cell by a standard gene introduction method described above, or a virus particle containing the genome of the virus into which an inventive DNA has been inserted is infected to a host cell, whereby introducing the genome of said virus into the host cell.

In order to screen for an inventive transformant, a marker gene is introduced into a host cell simultaneously with an inventive vector and the cell is cultured in a manner suitable to the nature of the marker gene. For example, when the marker gene is a gene which impart the host cell with a resistance to a lethally active screening drug, then the cell into which the inventive vector has been introduced is cultured in a medium supplemented with said drug. The combination of such a drug resistance imparting gene and a screening drug may for example be the combination of a neomycin resistance imparting gene with neomycin, the combination of a hygromycin resistance imparting gene with hygromycin, and the combination of blasticidin S resistance imparting gene and blasticidin S. When the marker gene is a gene which compensates the auxotrophic nature of the host cell, then a minimum medium free from the relevant nutrition is used to culture the cell into which the inventive vector has been introduced.

In order to obtain an inventive transformant generated as a result of the introduction of an inventive DNA into a chromosome of a host cell, an inventive vector and a marker gene-carrying vector are made linear by a digestion with restriction enzymes, and then introduced as described above into a host cell, which is cultured usually for several weeks to screen for an intended transformant on the basis of the expression of the introduced marker gene. Alternatively, it is also possible to screen for an inventive transformant generated as a result of the introduction of an inventive DNA into a chromosome of a host cell by introducing an inventive vector comprising as a marker gene a gene providing a resistance to a screening drug describe above into a host cell as described above, subculturing this cell for several weeks in a medium supplemented with the screening drug, and then incubating a selected drug resistance clone surviving as a colony in a pure culture manner. In order to verify that the introduced inventive DNA has surely been integrated into the chromosome of the host cell, a standard genetic engineering method may be employed to prepare the genomic DNA of the cell, from which the presence of the inventive DNA is detected by a PCR using as a primer an oligonucleotide comprising a partial nucleotide sequence of the introduced inventive DNA or by a southern hybridization method using as a probe the introduced inventive DNA. Since such a transformant can be stored frozen and can be made viable upon any need of use, it allows the step for producing the transformant at every time of the experiment to be omitted, and allows the experiment to be conducted using a transformant whose characteristics and the handling condition for which are well established.

By culturing an inventive transformant obtained as described above, an inventive protein can be produced.

For example, when an inventive transformant is a microorganism, this transformant can be cultured using any culture medium containing carbon sources, nitrogen sources, organic salts and inorganic salts, as appropriate, used in an ordinary culture of an ordinary microorganism. The culture can be conducted in accordance with a usual procedure for an ordinary microorganism, such as a solid culture, liquid culture (rotary shaking culture, reciprocal shaking culture, Jar Fermenter, tank culture and the like). The culture temperature and the pH of the medium may appropriately be selected from the range enabling the growth of the microorganisms, and the culture is conducted usually at a temperature of about 15° C. to about 40° C. at a pH of about 6 to about 8. The culture time period is usually about 1 day to about 5 days, although it may vary depending on various culture conditions. When an expression vector comprising a promoter of a temperature shift type or an induction type such as an IPTG induction type, the induction time is preferably within 1 day, usually several hours.

When a transformant described above is an animal cell such as an insect cell, then the transformant can be cultured using a culture medium employed in an ordinary culture of an ordinary cell. When such a transformant was prepared using a screening drug, then the culture is conducted preferably in the presence of the relevant drug. In the case of a mammalian cell, the culture is conducted for example in a DMEM medium supplemented with FBS at the final concentration of 10% (v/v) (NISSUI and the like) at 37° C. in the presence of 5% CO₂ with replacing the culture medium with a fresh medium every several days. When the culture became confluent, a PBS solution supplemented with trypsin for example at a concentration of about 0.25 (w/v) is added to disperse the culture into individual cells, which are subjected to a several-fold dilution and then inoculated to new dishes where they are further cultured. Similarly in the case of an insect cell, an insect cell culture medium such as a Grace's medium containing 10% (v/v) FBS and 2% (w/v) Yeastlate is employed to conduct the culture at a temperature of 25° C. to 35° C. In this case, a cell which tends to be peeled off from a dish easily such as a Sf21 cell can be dispersed by pipetting instead of using a trypsin solution, whereby continuing the subculture. In the case of a transformant containing a vector of a virus such as a baculovirus, the culture time period is preferably shorter than the time period allowing a cytoplasm effect to be evident to cause the cell death, for example up to 72 hours after the virus infection.

An inventive protein produced by an inventive transformant can be recovered appropriately by a combination of ordinary isolation and purification methods, and a fraction containing the inventive protein can be obtained by collecting the transformant cells by a centrifugation after completion of the culture, suspending the collected cells in an ordinary buffer solution, pelletizing the cells for example using Polytron, ultrasonic treatment, Dounce homogenizer and the like, and then centrifuging the pelletized cell fluid to recover the supernatant. A further purified inventive protein can be recovered by subjecting the supernatant fraction described above to various chromatographic procedures such as ion exchange chromatography, hydrophobic interaction chromatography, gel filtration chromatography, affinity chromatography and the like. When an inventive protein or a polypeptide comprising its partial amino acid sequence is produced as a fusion protein with GST, the purification can be accomplished by an affinity chromatography using a glutathione sepharose (Amersham Pharmacia).

An inventive protein thus produced can be employed as an immune antigen for producing an antibody which recognizes an inventive protein or a polypeptide comprising its partial amino acid sequence, and can also be employed in an assay for screening for a substance which binds to the inventive protein.

Using an inventive protein produced as described above as an immune antigen, an animal such as mouse, rabbit, chicken and the like is immunized in accordance with an immunological procedure described in Frederick M. Ausubel et al., Short Protocols in Molecular Biology 3nd Edition, John Wiley & Sons, Inc, whereby producing an antibody which recognizes an inventive protein or a polypeptide comprising its partial amino acid sequence. More typically and in one example, an inventive protein as an antigen is mixed with a complete Freunds adjuvant to form an emulsion. The resultant emulsion is administered subcutaneously to a rabbit. After about 4 weeks, an antigen emulsified in an incomplete Freunds adjuvant is administered. If necessary, a similar administration is further conducted every two weeks. The blood is sampled to obtain a serum fraction, the antibody titre of which against the inventive protein is then verified. The resultant serum fraction having the antibody titre which recognizes the inventive protein or a polypeptide comprising its partial amino acid sequence is fractionated in accordance for example with an ordinary ammonium sulfate sedimentation method, whereby obtaining an IgG which recognizes the inventive protein or a polypeptide comprising its partial amino acid sequence.

Alternatively, a polypeptide comprising a partial amino acid sequence of an inventive protein is synthesized chemically and administered as an immune antigen to an animal, whereby producing an antibody which recognizes the inventive protein or a polypeptide comprising its partial amino acid sequence. As the amino acid sequence of a polypeptide employed as an immune antigen, an amino acid sequence which has as a low homology as possible with the amino acid sequences of other proteins and which has many differences from the amino acid sequence of an inventive protein possessed by an animal species to be immunized is selected for example from the amino acid sequences represented by SEQ ID NOs:1 to 3. A polypeptide having a length of 10 amino acids to 15 amino acids consisting of the selected amino acid sequence is synthesized chemically by a standard method and crosslinked for example with a carrier protein such as Limulus plyhemus hemocyanin using MBS and the like and then used to immunize an animal such as a rabbit as described above.

The resultant antibody which recognizes the inventive protein or a polypeptide comprising its partial amino acid sequence is then brought into contact with a test sample, and then a complex of the protein in the test sample with the antibody described above is detected by an ordinary immunological method, whereby detecting the inventive protein in the test sample. By means of such a detection procedure, the level or the distribution of an inventive protein for example in various tissues can be measured. Typically, when this antibody is employed as a diagnostic for a disease accompanied with a mental retardation or Alzheimer's disease, an application may become possible that an immune chromosome is employed to identify the presence or the stage of the disease described above.

A method for screening for a substance which binds to an inventive protein comprises (1) a step for bringing an inventive protein or a polypeptide comprising a partial amino acid sequence thereof into contact with a test sample and (2) a step for selecting a substance which binds to the inventive protein or said polypeptide.

A typical method may for example be a method in which a test sample is brought into contact with a column to which an inventive protein has been bound and the substance which is bound to the column is purified, or other known methods such as a western blotting.

A test sample used in the screening may for example be a cell extract, gene library expression product, synthetic low molecular compound, synthetic peptide, naturally occurring compound and the like.

By means of such a screening method, it is possible to isolate a ligand of an inventive protein or a protein having a function for regulating the activity of an inventive protein to which it is bound (including antibodies).

The transcription regulation ability of an inventive protein can be measured for example by an assay using a DNA encoding said protein and a reporter gene. In a typical procedure, one which is produced first is a transformant formed by introducing:

i) a chimera gene being formed by connecting, to a downstream of a promoter which is capable of functioning in a host cell, a DNA encoding a fusion protein of a DNA binding region of a transcription regulatory factor which is capable of functioning in the host cell and an inventive protein or a polypeptide comprising a partial amino acid sequence thereof, and, ii) a reporter gene being formed by connecting a DNA encoding a reporter protein to a downstream of a promoter containing a DNA to which the DNA binding region described in i) can be bound and a minimum promoter which is capable of functioning in a host cell, into a host cell (hereinafter designated as a test transformant). On the other hand, a transformant as a control in the measurement is produced by introducing: iii) a gene being formed by connecting, in the downstream of the promoter described in i), a DNA encoding the DNA binding region described in i), and, a reporter gene described in ii), into a host cell (hereinafter designated as a control transformant).

As a “DNA binding region of a transcription regulatory factor which is capable of functioning in a host cell” described in i) may for example be a DNA binding region of an yeast transcription regulatory factor GAL4, a bacteria repressor LexA and the like. A DNA encoding any of these is ligated to an inventive DNA or a DNA comprising a nucleotide sequence which is a partial nucleotide sequence of the inventive DNA and which encodes a partial amino acid sequence of an inventive protein with their reading frames being aligned, and then to the upstream of the ligated DNA a promoter capable of functioning in a host cell is operably connected, whereby obtaining a chimera gene being formed by connecting, to a downstream of a promoter which is capable of functioning in a host cell, a DNA encoding a fusion protein of a DNA binding region of a transcription regulatory factor which is capable of functioning in the host cell and an inventive protein or a polypeptide comprising a partial amino acid sequence thereof described in i). The “DNA comprising a nucleotide sequence which is a partial nucleotide sequence of the inventive DNA and which encodes a partial amino acid sequence of an inventive protein” described above may for example a DNA comprising a nucleotide sequence encoding an amino acid sequence from about amino acid No. 100 to about 800 in the amino acid sequence represented by any of SEQ ID NOs:1 to 3.

A promoter may for example be a inducible promoter such as a GAL1 promoter or a routinely expressed promoter such as an ADH promoter for example when a host cell is a budding yeast cell. When the host cell is an animal cell, then a Rous sarcoma virus (RSV) promoter and cytomegalovirus (CMV) promoter may be mentioned.

A reporter gene described in ii) may for example be a luciferase, secretor alkaline phosphatase, β-galactosidase, chloramphenicol acetyl transferase, growth factor and the like, with a reporter protein which is relatively stable in a host cell being preferred. A DNA encoding such a reporter gene is connected to a downstream of a promoter containing a DNA to which the DNA binding region described in i) can be bound and a minimum promoter which is capable of functioning in the host cell. For example, a DNA to which a DNA binding region of a GAL4 can be bound may for example be a Gal4 binding region of a GAL1 promoter, while a DNA to which a Lex A can be bound may for example be a LexA binding region. The minimum promoter which is capable of functioning in the host cell may for example be a DNA consisting of a minimum TATA box sequence derived from a gene capable of being expressed in a host cell, typically a DNA comprising a TATA box and a nucleotide sequence consisting of about 50 nucleotides near the transcription initiation point.

A “gene being formed by connecting, in the downstream of the promoter described in i), a DNA encoding the DNA binding region described in i)” in iii) described above can be obtained by binding, in a functional manner to a downstream of a “promoter which is capable of functioning in a host cell” used for producing a chimera gene described in i), a DNA encoding a “DNA binding region of a transcription regulatory factor which is capable of functioning in the host cell” used for producing a chimera gene described in i).

Each of genes described in i) to iii) is inserted for example into a vector, which is introduced in a combination described above into a host cell to obtain a transformant. As a vector containing a reporter gene described in ii), a commercially available vector such as a pFR-LUC (Stratagene) may be employed. As a host cell, a budding yeast cell or a mammalian cell such as a HeLa cell may be exemplified. When an intrinsic reporter gene capable of being utilized as a reporter gene described in ii) is possessed by the host cell, it may be utilized, and in such a case the introduction of a reporter gene can be omitted. In this context, a two hybrid can be accomplished by introducing both of a chimera gene, i.e., (a) a chimera gene encoding a fusion protein of one of a pair of the proteins capable of forming a complex consisting of two proteins in a host cell and a DNA binding region described in i), and (b) a chimera gene encoding a fusion protein of the other of the pair of the proteins capable of forming the complex consisting of the two proteins in the host cell and an inventive protein or a polypeptide comprising its partial amino acid sequence, instead of a gene described in i), into the host cell to obtain a test transformant.

A test transformant and a control transformant prepared as described above, for example after being allowed to stand for about several hours to several days, are subjected to the measurement of the reporter gene in each transformant. Typically, when a luciferase is employed as a reporter protein, a cell extract prepared from each transformant is combined with luciferrin which is a substrate for the luciferase, whereby allowing a luminescence to be emitted at an intensity in proportion with the luciferase level in the cell extract. Accordingly, by measuring this luminescence using a measuring device such as a luminometer, the luciferase level, and thus the luciferase (reporter) gene expression level, can be determined. When the expression level of the reporter gene in the test transformant is higher than the expression level of the reporter gene in the control transformant, the inventive protein or a polypeptide comprising its partial amino acid sequence encoded by the DNA introduced into said test transformant can be judged to have a transcription regulation ability (transcription activating ability in this case). On the contrary, when the expression level of the reporter gene in the test transformant is lower than the expression level of the reporter gene in the control transformant, the inventive protein or a polypeptide comprising its partial amino acid sequence encoded by the DNA introduced into said test transformant can be judged to have a transcription inhibiting ability.

For example, as evident from the Examples described later in this specification, an inventive protein or a polypeptide comprising its partial amino acid sequence has a transcription activating ability when using as a host cell a neuroblastoma such as an IMR32.

By using a test transformant described above, it is also possible to screen for a substance which alters the transcription regulation ability of an inventive protein. During a culture of the test transformant for 1 day or several days, a test substance is added into the medium to be brought into contact with said transformant, and then the expression level of a reporter gene in the presence of the test substance is measured. On the other hand, the expression level of the reporter gene under the condition involving no contact between the test transformant with the test substance is measured similarly. The expression level in the absence of the test substance and the expression level in the presence of the test substance are compared with each other, and a test substance which gives the expression level which may vary depending on the presence or absence of the test substance is selected, whereby screening for a substance which alters the transcription regulation ability of an inventive protein or a polypeptide comprising a partial amino acid sequence thereof encoded by the DNA introduced in said test transformant.

Then, a substance which alters the transcription regulation ability of an inventive protein in a cell unit (in other words, a substance which alters the transcriptional regulation by an inventive protein) may be screened for, for example, in an assay in which a test substance is brought into contact with a transformant obtained by introducing into a host cell a reporter gene obtained by ligating in a functional manner the expression regulation region of a DNA encoding the inventive protein. Thus, such a method may be a method for screening for a substance which alters the intracellular expression level of an inventive protein or a polypeptide comprising a partial amino acid sequence thereof comprising:

(1) a step for bringing a transformant being formed by introducing into a host cell a reporter gene obtained by ligating in a functional manner the expression regulation region of a DNA encoding said protein into contact with a test substance and then measuring the expression level of said reporter gene in the presence of the test substance, and, (2) a step for selecting a test substance which results in a expression level of said reporter gene, as measured in the step (1), which is different substantially from the expression level of said reporter gene in the absence of the test substance. Such a screening method is a method for screening for a substance altering the transcription regulation by an inventive protein or a polypeptide comprising its partial amino acid sequence, which method employs a so called reporter gene assay.

In this process, the concentration of a test substance to be brought into contact with said test transformant is usually about 0.1 μM to about 10 μM, preferably 1 μM to 10 μM. The time period during which said transformant and the test substance are brought into contact with each other is usually 18 hours to about 60 hours, preferably 24 hours to about 40 hours.

A transformant described above can be prepared as described below.

First, the expression regulation region of a DNA encoding an inventive protein is identified for example by a procedure involving (i) a step for determining the 5′-terminal by a standard method such as a 5′-RACE method (for example by using a 5′ full Race Core Kit (Takara)), oligocapping method, S1 primer mapping and the like; (ii) a step for obtaining a 5′-upstream region for example by using a Genome Walker Kit (Clontech) and measuring the promoter activity of the upstream region, and then cut out by a standard genetic engineering method, and then the expression regulation region thus cut out is operably ligated to a reporter gene (a gene whose expression can be analyzed) such as glucuronidase (GUS), luciferase, chloramphenicol acetyltransferase (CAT), β-galactosidase and green fluorescence protein (GFP), whereby preparing a reporter gene being formed by operably ligated with the expression regulation region of a DNA encoding the inventive protein. The expression “operably ligated” means here that a gene and one or more regulatory sequences are ligated in such a manner that it allows the gene to be expressed when an appropriate exogenous signal or factor is bound to the regulatory sequences. The term “expression regulation region” means a sequence which contains a promoter element under a cell specific or tissue specific control or a promoter element sufficient for inducing a promoter-dependent gene expression induced by a exogenous signal or factor (such as a transcription activating protein) and which is also required for promoting the transcription. Such an element may be located on either the 5′ region or the 3′ region of the native gene. Subsequently, the reporter gene being formed by operably ligated with the expression regulation region of the DNA encoding an inventive protein is inserted by a standard genetic engineering method into a vector capable of being utilized in a cell to which said reporter gene is to be introduced, whereby producing a plasmid. Then, said plasmid is introduced into a cell. A method for such a introduction may for example be a calcium phosphate method, electroinduction, DEAE dextran method, micelle formation and the like. The calcium phosphate method may be a method described in Grimm, S. et al., Proc. Natl. Acad. Sci. USA, 93, 10923–10927, the electroinduciton and DEAE dextran method may for example be those described in Ting, A. T. et al. EMBO J., 15, 6189–6196, and the micelle formation may for example be a method described in Hawkins, C. J. et al., Proc. Natl. Acad. Sci. USA, 93, 13786–13790. When a micelle formation is employed, a commercially available reagent such as Lipofectamine (Gibco) or Fugene (Boehringer) may be utilized.

A cell which has been introduced with a plasmid described above is cultured in a medium providing a screening condition suitable to a screening marker gene for example by utilizing the screening marker gene which has previously been contained in vector, whereby screening for said transformant (a cell into which an inventive gene has transiently been introduced). It is also possible to screening further continuously to obtain said transformant which now became a stable transformant into whose chromosome said DNA has been introduced. In order to verify that the introduced DNA has been integrated into a chromosome present in the cell, the genomic DNA of said cell may be produced in accordance with a standard genetic engineering method and then the presence of said DNA in the genomic DNA may be detected and identified by means of a PCR employing a DNA comprising a partial nucleotide sequence of said DNA as a primer, or by a southern hybridization method employing a DNA comprising a partial nucleotide sequence of said DNA as a probe.

Said transformant may be prepared also from a transformed non-human animal tissue described below by an ordinary procedure.

A substance screened for by the searching procedures described above or a pharmaceutically acceptable salt may be utilized as an inventive expression regulating agent comprising it as an active ingredient which is obtained by formulating said active ingredient in a pharmaceutically acceptable carrier.

In a screening method described above, a method for “measuring the expression level of a reporter gene” may be any method in which the expression level of the reporter gene in said transformant can be measured continuously or intermittently over a certain period. The expression “selecting a substance which is different substantially” means to select a compound capable of giving an expression level in the presence of the test substance which is higher by 10% or more, preferably 30% or more, more preferably 50% or more, than that in the absence of the substance. For example, when the reporter gene is a luciferase gene, a commercially available product such as a luciferase assay reagent (Promega) may be employed.

A method for analyzing a genotype of a gene encoding an inventive protein possessed by an individual animal such as a human may for example be a method for investigating whether a nucleotide sequence encoding an inventive protein in a nucleic acid such as a genomic DNA or RNA contained in a sample obtained from a test individual contains a nucleotide sequence encoding an amino acid sequence which is different from the amino acid sequence of a standard protein.

Typically, first, a sample is obtained from a test individual such as a human, and from said sample a genomic DNA or RNA is prepared. For example, from a sample of a cellular tissue such as a hair, peripheral blood, oral cavity epithelium and the like, a genomic DNA can be prepared in accordance with a standard method described for example in M. Muramatsu, “Labomanual Genetic Engineering”, Maruzen (1988) or TAKARA PCR Technical News No. 2, TAKARA SHUZO, (1991.9). For example, when the sample is a hair, 2 or 3 hairs are washed with a sterilized water and then with ethanol, cut into 2 to 3 mm pieces, which are combined with 200 μl of a BCL-Buffer [10 mM Tris-HCl (pH7.5), 5 mM MgCl₂, 0.32M sucrose, 1 Triton X-100] followed by a Proteinase K at the final concentration of 100 μl/ml and SDS at the final concentration of 0.5 (w/v). The mixture thus obtained is incubated at 70° C. for 1 hour, and then subjected to a phenol/chloroform extraction to obtain a genomic DNA. When the sample is a peripheral blood, the sample is treated using a DNA-Extraction kit (Stratagene) and the like to obtain a genomic DNA. When the sample is a fresh biopsy test sample, an RNA can be prepared from said sample for example by using a TRIZOL reagent (GIBCO). By using the resultant RNA as a template in the presence of the effect of a reverse transcriptase, a cDNA can be synthesized.

From a genomic DNA, cDNA and the like thus prepared, a DNA encoding an inventive protein is amplified for example by means of a PCR, if necessary.

A primer which may be employed for amplifying a DNA encoding an inventive protein from a genomic DNA by means of a PCR may for example be:

a polynucleotide consisting of 10 to 50 nucleotides capable of being annealed under a polymerase chain reaction condition with a polynucleotide consisting of the nucleotide sequence represented by SEQ ID NO:4, 5, 6 or 54 or the nucleotide sequence complementary to said nucleotide sequence, and typically,

a polynucleotide consisting of 10 to 50 nucleotides comprising a partial nucleotide sequence of the nucleotide sequence represented by SEQ ID NO:4, 5, 6 or 54 or the nucleotide sequence complementary to said partial nucleotide sequence. More specifically, the polynucleotide consisting of the nucleotide sequence represented by SEQ ID NO:7 or 8 may be exemplified as a forward primer, while the polynucleotide consisting of the nucleotide sequence represented by SEQ ID NO:9 or 10 may be exemplified as a reverse primer.

In a genomic DNA, an inventive protein is encoded as being divided in 8 exons (hereinafter an exon containing the nucleotide sequence encoding the inventive protein is designated as exon 1 to 8 in this order from the 5′-upstream side). For example, the nucleotide sequence represented by SEQ ID NO:4 which encodes an inventive protein derived from a human is contained in the exons as being divided into the following 8 portions:

Nucleotide sequence of Nucleotide Nos.1 to 276: Exon 1

Nucleotide sequence of Nucleotide Nos.277 to 428: Exon 2

Nucleotide sequence of Nucleotide Nos.429 to 531: Exon 3

Nucleotide sequence of Nucleotide Nos.532 to 799: Exon 4

Nucleotide sequence of Nucleotide Nos.800 to 909: Exon 5

Nucleotide sequence of Nucleotide Nos.910 to 1045: Exon 6

Nucleotide sequence of Nucleotide Nos.1046 to 2481: Exon 7

Nucleotide sequence of Nucleotide Nos.2482 to 3252: Exon 8

Thus, a DNA containing the nucleotide sequence of an exon of a genome gene encoding an inventive protein and a part of the nucleotide sequence of the intron adjacent to said exon may be amplified from genomic DNA. A primer which can be employed for amplifying such a DNA may for example be:

a polynucleotide consisting of 10 to 50 nucleotides capable of being annealed under a polymerase chain reaction condition with a polynucleotide consisting of the nucleotide sequence represented by any of SEQ ID NOs:43 to 51 or the nucleotide sequence complementary to said nucleotide sequence, and typically,

a polynucleotide consisting of 10 to 50 nucleotides comprising a partial nucleotide sequence of the nucleotide sequence represented by any of SEQ ID NOs:43 to 51 or the nucleotide sequence complementary to said partial nucleotide sequence. Such a primer can be designed for example as described below.

A forward primer for amplifying a DNA containing the exon 1 and a sequence in the non-translation region 5′-upstream thereof; designed based on the nucleotide sequence represented by SEQ ID NO:43.

e.g.) Polynucleotide consisting of the nucleotide sequence represented by SEQ ID NO:11 or 12.

A reverse primer for amplifying a DNA containing the exon 1 and an intron sequence 3′-downstream thereof; designed based on the nucleotide sequence complementary to the nucleotide sequence represented by SEQ ID NO:44.

e.g.) Polynucleotide consisting of the nucleotide sequence represented by SEQ ID NO:13 or 14.

A forward primer for amplifying a DNA containing the exon 2 and an intron sequence 5′-upstream thereof; designed based on the nucleotide sequence represented by SEQ ID NO:44.

e.g.) Polynucleotide consisting of the nucleotide sequence represented by SEQ ID NO:15 or 16.

A reverse primer for amplifying a DNA containing the exon 2 and an intron sequence 3′-downstream thereof; designed based on the nucleotide sequence complementary to the nucleotide sequence represented by SEQ ID NO:45.

e.g.) Polynucleotide consisting of the nucleotide sequence represented by SEQ ID NO:17 or 18.

A forward primer for amplifying a DNA containing the exon 3 and an intron sequence 5′-upstream thereof; designed based on the nucleotide sequence represented by SEQ ID NO:45.

e.g.) Polynucleotide consisting of the nucleotide sequence represented by SEQ ID NO:19 or 20.

A reverse primer for amplifying a DNA containing the exon 3 and an intron sequence 3′-downstream thereof; designed based on the nucleotide sequence complementary to the nucleotide sequence represented by SEQ ID NO:46.

e.g.) Polynucleotide consisting of the nucleotide sequence represented by SEQ ID NO:21 or 22.

A forward primer for amplifying a DNA containing the exon 4 and an intron sequence 5′-upstream thereof; designed based on the nucleotide sequence represented by SEQ ID NO:46.

e.g.) Polynucleotide consisting of the nucleotide sequence represented by SEQ ID NO:23 or 24.

A reverse primer for amplifying a DNA containing the exon 4 and an intron sequence 3′-downstream thereof; designed based on the nucleotide sequence complementary to the nucleotide sequence represented by SEQ ID NO:47.

e.g.) Polynucleotide consisting of the nucleotide sequence represented by SEQ ID NO:25 or 26.

A forward primer for amplifying a DNA containing the exon 5 and an intron sequence 5′-upstream thereof; designed based on the nucleotide sequence represented by SEQ ID NO:47.

e.g.) Polynucleotide consisting of the nucleotide sequence represented by SEQ ID NO:27 or 28.

A reverse primer for amplifying a DNA containing the exon 5 and an intron sequence 3′-downstream thereof; designed based on the nucleotide sequence comprementaly to the nucleotide sequence represented by SEQ ID NO:48.

e.g.) Polynucleotide consisting of the nucleotide sequence represented by SEQ ID NO:29 or 30.

A forward primer for amplifying a DNA containing the exon 6 and an intron sequence 5′-upstream thereof; designed based on the nucleotide sequence represented by SEQ ID NO:48.

e.g.) Polynucleotide consisting of the nucleotide sequence represented by SEQ ID NO:31 or 32.

A reverse primer for amplifying a DNA containing the exon 6 and an intron sequence 3′-downstream thereof; designed based on the nucleotide sequence comprementaly to the nucleotide sequence represented by SEQ ID NO:49.

e.g.) Polynucleotide consisting of the nucleotide sequence represented by SEQ ID NO:33 or 34.

A forward primer for amplifying a DNA containing the exon 7 and an intron sequence 5′-upstream thereof; designed based on the nucleotide sequence represented by SEQ ID NO:49.

e.g.) Polynucleotide consisting of the nucleotide sequence represented by SEQ ID NO:35 or 36.

A reverse primer for amplifying a DNA containing the exon 7 and an intron sequence 3′-downstream thereof; designed based on the nucleotide sequence complementary to the nucleotide sequence represented by SEQ ID NO:50.

e.g.) Polynucleotide consisting of the nucleotide sequence represented by SEQ ID NO:37 or 38.

A forward primer for amplifying a DNA containing the exon 8 and an intron sequence 5′-upstream thereof; designed based on the nucleotide sequence represented by SEQ ID NO:50.

e.g.) Polynucleotide consisting of the nucleotide sequence represented by SEQ ID NO:39 or 40.

A reverse primer for amplifying a DNA containing the exon 8 and a sequence in the non-translation region 3′-downstream thereof; designed based on the nucleotide sequence comprementaly to the nucleotide sequence represented by SEQ ID NO:51.

e.g.) Polynucleotide consisting of the nucleotide sequence represented by SEQ ID NO:41 or 42.

A primer which may be employed for amplifying a DNA encoding an inventive protein from a cDNA by means of a PCR may for example be:

a polynucleotide consisting of 10 to 50 nucleotides capable of being annealed under a polymerase chain reaction condition with a polynucleotide consisting of the nucleotide sequence represented by any of SEQ ID NO:4 to 6 or the nucleotide sequence complementary to said nucleotide sequence, and typically, a polynucleotide consisting of 10 to 50 nucleotides comprising a partial nucleotide sequence of the nucleotide sequence represented by any of SEQ ID NO:4 to 6 or the nucleotide sequence complementary to said partial nucleotide sequence. More specifically, the polynucleotide consisting of the nucleotide sequence represented by SEQ ID NO:7 or 8 may be exemplified as a forward primer, while the polynucleotide consisting of the nucleotide sequence represented by SEQ ID NO:9 or 10 may be exemplified as a reverse primer. Any of these polynucleotides can be prepared for example by using a commercially available automatic DNA synthesizer employing a β-cyanoethyl phosphoamidite method or thiophosphite method.

When a PCR is conducted using a polynucleotide described above as a primer, two primers, i.e., forward and reverse primers, are employed usually in combination. The PCR can be conducted in accordance with a method described for example in Saiki et al., Science, Vol. 230, p. 1350 to 1354 (1985). For example, an amplification buffer solution containing about 1.5 mM to about 3.0 mM magnesium chloride and the like, to which about 10 pmol of each of the polynucleotides employed as primers is added and to which a DNA polymerase, 4 nucleotides (dATP, dTTP, dGTP, dCTP) and about 100 ng of a genomic DNA or about 10 ng of a cDNA as a template has previously been added, is prepared. The resultant amplification buffer solution is subjected to 35 cycles, each cycle involving an incubation at 95° C. for 1 minutes followed by 68° C. for 3 minutes.

The nucleotide sequence of a DNA amplified as described above using a nucleic acid in a test sample as a template is determined, whereby determining whether the nucleotide sequence encoding an inventive protein in the nucleic acid of the test sample contains the nucleotide sequence encoding the amino acid sequence which is different from the amino acid sequence of the standard protein.

More specifically, a DNA amplified by a PCR as described above is subjected to a low melting point agarose gel electrophoresis, and recovered from the gel, and the recovered DNA is subjected for example to a direct sequence [BioTechniques, 7, 494 (1989)], whereby determining the nucleotide sequence of said DNA. The nucleotide sequence may be analyzed in accordance with a Maxam Gilbert Method (for example, described in Maxam. A. M. & W. Gilbert, Proc. Natl. Acad. Sci. USA, 74, 560, 1977 and the like) or a Sanger method (for example, described in Sanger, F. & A. R. Coulson, J. Mol. Biol., 94, 441, 1975., Sanger, F/. & Nicklen and A. R. Coulson., Proc. Natl. Acad. Sci. USA., 74, 5463, 1977 and the like). When an automatic DNA sequencer such as an ABI model 377, a relevant DNA sequence kit such as ABI BigDye terminator cycle sequencing ready reaction kit can be employed to prepare a sample for the sequencing.

Alternatively, a DNA amplified as described above using a nucleic acid in a test sample as a template is subjected to an electrophoresis to determine the mobility, and the measured mobility is examined for the difference from the mobility of a DNA encoding the relevant region of a standard protein, whereby determining whether the nucleotide sequence encoding an inventive protein in the nucleic acid of the test sample contains the nucleotide sequence encoding the amino acid sequence which is different from the amino acid sequence of the standard protein.

More specifically, for example upon amplifying a DNA by a PCR as described above, a ³²P-labeled polynucleotide is employed as a primer in accordance with a standard method to conduct the PCR as described above. A DNA encoding the relevant region of a standard DNA is also amplified similarly. The amplified DNA is subjected to an electrophoresis in accordance for example with an SSCP (single strand conformation polymorphism) method described in Hum. Mutation, Vol. 2, p. 338. Typically, the amplified DNA is denatured with heating to dissociate into single-stranded DNAs, which are subjected to a non-denaturing polyacrylamide electrophoresis to separate into individual single-stranded DNAs. The buffer solution employed in this electrophoresis may for example be a Tris-phosphate (pH7.5–8.0), Tris-acetate (pH7.5–8.0), Tris-borate (pH7.5–8.3) and the like. If necessary, the buffer may contain EDTA and the like. The condition of the electrophoresis may involve a constant power of 30 W to 40 W, a running temperature of room temperature (about 20° C. to about 25° C.) or 4° C., and a running period of 1 hour to 4 hours. Subsequently, the gel after the electrophoresis is transferred onto a filter paper, with which an X-ray film is brought into a close contact, and then placed in a suitable light-protected cassette, where the radioactivity of individual radio-labeled single-stranded DNAs is exposed to the film. The film is developed, and the resultant autoradiogram is observed to compare the mobility between the DNA amplified using the nucleic acid in the test sample as a template and the DNA encoding the relevant region of the standard protein. When the mobility of these DNAs is different from each other, then the nucleotide sequence encoding the inventive protein in the nucleic acid in the test sample is judged to contain the nucleotide sequence encoding the amino acid sequence which is different from the amino acid sequence of the standard protein. Furthermore, the gel containing the DNA having a different mobility is extracted with a boiling water to recover the DNA contained therein, which is employed as a template to perform a PCR, whereby amplifying said DNA, which is subjected to a low melting point agarose gel electrophoresis, and recovered from the gel, and then subjected to a direct sequence, whereby determining the nucleotide sequence of said DNA. In this manner, the nucleotide sequence encoding the amino acid sequence which is different from the amino acid sequence of the standard protein can be identified.

By investigating the pattern of the hybridization between a nucleic acid such as a genomic DNA, cDNA or mRNA in a test sample or a DNA amplified using as a template a nucleic acid in a test sample as described above and a polynucleotide consisting of 10 to 5000 nucleotides capable of hybridizing under a stringent condition with a polynucleotide consisting of the nucleotide sequence represented by SEQ ID NO:4, 5, 6 or 54 or the nucleotide sequence complementary to said nucleotide sequence, it can be determined whether the nucleotide sequence encoding an inventive protein in the nucleic acid of the test sample contains the nucleotide sequence encoding the amino acid sequence which is different from the amino acid sequence of a standard protein.

A “polynucleotide consisting of 10 to 5000 nucleotides capable of hybridizing under a stringent condition with a polynucleotide consisting of the nucleotide sequence represented by SEQ ID NO:4, 5, 6 or 54 or the nucleotide sequence complementary to said nucleotide sequence” may for example be a polynucleotide consisting of 10 to 5000 nucleotides comprising a partial nucleotide sequence of the nucleotide sequence represented by SEQ ID NO:4, 5, 6 or 54 or the nucleotide sequence complementary to said partial nucleotide sequence.

A nucleic acid such as a genomic DNA, cDNA or mRNA prepared from a test sample or a DNA amplified using as a template a nucleic acid in a test sample as described above is mixed with a polynucleotide described above and subjected to a hybridization under a stringent condition. The hybridization can be accomplished in accordance with a standard dot blot hybridization, southern blot hybridization or northern blot hybridization described for example in J. Sambrook, E. F. Frisch, T. Maniatis, Molecular Cloning, 2nd Edition, Cold Spring Harbor Laboratory (1989) or by a mismatch detection method utilizing a Taq MutS which is an enzyme capable of binding to a mismatch hybridization site [described for example in Biswas, I. And Hsieh, P. J. Biol. Chem., 271, 9, pp. 5040–5048 (1996) or Nippon Gene information 1999, No. 125, Nippon Gene, TOYAMA].

A stringent condition in the hybridization may involve, for example, a prehybridization and a hybridization conducted in the presence of 6×SSC (0.9M sodium chloride, 0.09M sodium citrate), 5× Denhart's solution (0.1 (w/v) ficoll 400, 0.1 (w/v) polyvinyl pyrrolidone), 0.1 SA), 0.5 (w/v) SDS and 100 μg/ml denatured salmon sperm DNA, or in a DIG ESY Hyb solution (Boehringer Mannheim) containing 100 μg/ml denatured salmon sperm DNA, followed by an incubation, as a washing process, at room temperature for 15 minutes in the presence of 1×SSC (0.15M sodium chloride, 0.015M sodium citrate) and 0.5 DS, followed by an incubation for 30 minutes in the presence of 0.1×SSC (0.015M sodium chloride, 0.0015M sodium citrate) and 0.5 DS. The incubation temperature in the prehybridization, hybridization and washing process may vary depending on the length and the composition of the polynucleotide employed as a probe, and is generally identical to the Tm of the probe or a temperature higher slightly than the Tm. Typically, in the case for example of a base pair when a inter-base hydrogen bond is formed between the probe and the nucleic acid in the sample in the hybridization, Tm is the sum of the all values of the base pairs forming hydrogen bonds with one pair of A and T being assigned to 2° C. and one pair of G and C being assigned to 4° C. A temperature identical to the Tm value thus calculated or a temperature which is higher by 2 to 3° C. may be selected.

In a typical procedure of a dot hybridization, a nucleic acid such as a genomic DNA, cDNA and the like prepared from a test sample or a DNA amplified using as a template a nucleic acid in a test sample as described above is incubated at 90° C. to 100° C. for 3 to 5 minutes, and then spotted onto a nylon filter [Hybond N (Amersham Pharmacia) and the like], and then the spotted filter is dried on a filter paper, and then irradiated with a UV light, whereby immobilizing the DNA on the filter. Then, the resultant DNA-immobilizing filter and the probe described above are incubated for example at 40° C. to 50° C. for 10 hours and 20 hours to effect a hybridization, and the hybrid containing the probe is detected in accordance with a standard method. When the probe employed is a radioactive probe labeled with a radioactive isotope such as ³²p, the filter after the hybridization is exposed to an X-ray film whereby detecting a hybrid containing the probe. When the probe employed is a non-radioactive probe labeled with a biotinylated nucleotide, a hybrid containing said probe is labeled with an enzyme such as a biotinylated alkaline phosphatase via streptoavidine, and the color development or luminescence of the substrate due to the enzyme reaction is detected, whereby detecting a hybrid containing the probe. It is also possible to use a non-radioactive probe which is labeled directly via a spacer with an enzyme such as an alkaline phosphatase or peroxidase. When the DNA from the test sample gave no detectable hybrid containing the probe or when the DNA from the test sample gave a level of the hybrid which is higher than that of the level of the hybrid given by a DNA encoding the relevant region of a standard protein, then it can be judged that the nucleic acid in the test sample contains a nucleotide sequence different from the nucleotide sequence of the probe employed.

The procedure of a southern blot hybridization or northern blot hybridization may involve digesting a nucleic acid such as a genomic DNA, cDNA or mRNA prepared from a test sample or a DNA amplified using as a template a nucleic acid in a test sample as described above with a restriction enzyme if necessary, followed by an electrophoresis such as an agarose gel electrophoresis or polyacrylamide gel electrophoresis to effect a fractionation, followed by blotting onto a filter such as a nitrocellulose filter or nylon filter. The resultant filter is treated as described above and then hybridized with a probe. When the level of the hybrid containing the probe or the length of the nucleic acid forming a hybrid with the probe is different between the nucleic acid from the test sample and the relevant nucleic acid of a standard protein, then the nucleotide sequence encoding the inventive protein in the nucleic acid in the test sample is judged to contain the nucleotide sequence encoding the amino acid sequence which is different from the amino acid sequence of the standard protein.

When using a mismatch detection method utilizing a Taq MutS which is an enzyme capable of binding to a mismatch hybridization site, the binding characteristics of the Taq Muts, such as a high stability to a heat (0 to 75° C.) and an ability of maintaining the activity even at a high temperature to recognize the DNA mismatch base pair whereby enabling the binding, are utilized to detect the mismatch base pair by conducting a gel shift assay using a non-denatured polyacrylamide gel or a dot blotting method on a solid phase such as a nylon filter or nitrocellulose filter. When a mismatch is detected, then it can be judged that the nucleic acid in the test sample contains a nucleotide sequence different from the nucleotide sequence of the probe employed.

A standard protein can be selected from inventive proteins as appropriate, and may for example be an inventive protein consisting of the amino acid sequence represented by SEQ ID NO:1, 2 or 3.

An inventive kit can be applied to a method for investigating the presence of a gene, the genotype, the protein type and the like utilizing a known method such as a hybridization (for example, dot blot hybridization, Southern blot hybridization, Northern blot hybridization, mismatch detection utilizing a Taq MutS), an SSCP method (method utilizing the mobility of a DNA), a PCR method (for example, genomic PCR, cDNA PCR and the like) as described above. In such a case, an inventive kit may contain a reagent required for a known method described above, or may be used in combination with such a reagent.

An analysis of the genotype of a gene encoding an inventive protein possessed by an individual animal such as a human, which can be conducted as described above, is useful in the diagnosis, prophylaxis and therapy of a disease induced by the variation in the inventive protein.

Furthermore, since a gene encoding an inventive protein is a gene which is mapped between STS markers D11S913 and D11S1889 positioned in 11q13 on a human chromosome, more specifically, a gene which is present at a position whose distance from D11S913 is about 175 kbp in the direction of the telomere, it can be expected to be utilized as a tightly linked gene marker with regard to Bardet-Biedl syndrome Type I, and thus can be applied to the diagnosis of such a disease based on the methods described above.

The invention also provides a method for promoting the expression of a drebrin 1 in a mammal comprising a step for providing the mammalian cell with the DNA encoding an inventive protein in a position enabling the expression of said DNA in said cell [inventive promoting method].

Such a mammalian cell may for example be a cell derived from a mammal such as human, monkey, mouse, rat, hamster and the like. Such a cell may be a cell which constitutes a population having identical functions and morphologies, or a cell present in the body of said mammalian animal.

Accordingly, when the mammalian animal is a human, a range from a human receiving a so called gene therapy to a cell line employed in various experiments is contemplated, while when the mammalian animal is a non-human animal then a range from a non-human animal receiving a so called gene therapy to an animal model or a cell line employed in various experiments is contemplated. In the latter case, a preferred species is rat, mouse and the like.

Moreover, a case in which a mammalian cell is a cell in the body of a mammalian animal which can be diagnosed to suffer from a disease accompanied with a mental retardation or from Alzheimer's disease can be exemplified as a more typical case.

A method for preparing a DNA encoding an inventive protein may be prepared in accordance with a method equivalent to that described above.

Using such a DNA thus prepared, a transformant is prepared as described below, whereby obtaining a transformant in which said DNA is provided in a position which enables its expression in the mammalian cell.

In an inventive expression promoting method, the phrase “provided in a position enabling the expression” means that a DNA molecule is placed in the position adjacent to a DNA sequence directing the transcription and the translation of its nucleotide sequence (i.g., promoting the production of an inventive protein or its RNA molecule).

The expression level of the DNA of an inventive protein may be any level which is sufficient to promote the expression of a drebrin 1 when compared with a cell into which no DNA of the inventive protein has been introduced. In such a case, the DNA encoding the inventive protein may be a DNA encoding the entire or a part of the inventive protein.

In an expression promoting method described above, it is also possible to promote a drebrin 1 by preparing a transformant in which a DNA encoding an inventive protein is integrated into a genome.

In an expression promoting method described above, a gene construct employed for introducing a DNA encoding an inventive protein into a mammalian cell (hereinafter sometimes referred to as an inventive gene construct) and a method for accomplishing a gene import may employ a virus vector having an affinity to the mammalian cell to which said DNA is to be introduced, such as a retrovirus vector, adenovirus vector, adeno-associated virus vector or others. For example, known vectors described in Miller, Human Gene Therapy 15 to 14, 1990; Friedman, Science 244:1275 to 1281, 1989; Eglitis and Anderson, BioTechniques 6:608 to 614, 1988; Tolstoshev and Anderson, Current opinion in Biotechnology 1;55 to 61, 1990; Sharp, The Lancet 337:1277 to 1278, 1991; Cornetta et al, Nucleic Acid Research and Molecular Biology 36:311 to 322, 1987; Anderson, Science 22-:401 to 409, 1984; Moen, Blood Cells 17:407 to 416, 1991; Miller et al., Biotechniques 7:980 to 990, 1989; Le Gai La Salle et al., Science 259:988 to 990, 1993; and Johnson) Chest 107:77S to 83S, 1995 and the like may be exemplified. The retroviruses described for example in Rosenberg et al, N. Engl. J. Med 323:370, 1990; Anderson et al., U.S. Pat. No. 5,399,346 have extensively developed, and have already been introduced into a clinical stage. For example, when said cell is an animal cell, those which may be exemplified are an SV40 virus promoter, cytomegalovirus promoter (CMV promoter), Rous sarcoma virus promoter (RSV promoter, β actin gene promoter, aP2 gene promoter and the like. It is also possible to use a commercially available vector containing any of these promoters upstream of the multiple cloning site.

Said DNA may be placed under the control of a promoter which allows a DNA of an inventive protein to be expressed constitutively. Such a DNA may also be placed under the control of a promoter which regulates the expression of a DNA of an inventive protein via an environmental stimulation. For example, said DNA may be expressed using a tissue-specific or cell type-specific promoter or a promoter which is activated by a chemical signal or exogenous signal such as a drug or by the introduction of a drug.

It is also possible to employ an non-viral technique. Those which may be exemplified are a lipofection described in Felgner et al., Proc. Natl. Acad. Sci. USA 84:7413, 1987; Ono et al., Neurosci. Lett. 117:259, 1990; Brigham et al., Am. J. Med. Sci. 298:278, 1989; Staubinger et al., Meth. Enz. 101:512, 1983, asialoorosomucoid-polylysine conjugation (Wu et al., J. Biol. Chem. 263:14621, 1988, lipofection described in Wu et al., J. Biol. Chem. 264:16985, 1989 and the like, microinjection described in Wolff et al., Science 247:1465, 1990 and the like, calcium phosphate method, DEAE dextran method, electroporation, protoplast fusion method, liposome method and the like.

While in any of the technologies described above an inventive gene construct is applied (for example by an infusion) to the site where an underexpression of a drebrin 1 is expected, it may be applied to a tissue near the site where an event such as an underexpression of a drebrin 1 is expected or to a vessel supplying to the cell assumed to undergo an underexpression of a drebrin 1.

In an inventive gene construct, the expression of a DNA (cDNA) of an inventive protein can be directed by an appropriate promoter (for example, a promoter of human cytomegalovirus (CMV), simian virus 40 (SV40) or metallothionein and the like), and may also be regulated by an appropriate mammalian animal regulatory factor. For example, a DNA of an inventive protein can be expressed if necessary using an enhancer known to direct predominantly to the expression of the DNA in a neurocyte. Such an enhancer may be any enhancer whose expression is characterized to be specific to a tissue or cell. When a clone of a DNA (genome) of an inventive protein is employed as a gene construct (for example, a clone of a DNA (genome) of an inventive protein isolated by the hybridization with a DNA (cDNA) of an inventive protein described above), the regulation can be accomplished also via a cognate regulatory sequence, if necessary together with a regulatory sequence derived from an heterologous source containing any promoter or regulatory element described above.

When an expression promoting method described above is applied as a method for a gene therapy, it can be used by a direct administration of the gene of an inventive protein into a cell. While the gene which may be employed may be any gene which has been produced or isolated by a standard method, a most convenient production can be accomplished by an in vivo transcription employing the gene of an inventive protein under the control of a highly efficient promoter (for example, human cytomegalovirus promoter). The administration of the gene of an inventive protein can be conducted by any of the direct nucleic acid administration methods described above.

An expression promoting method described above can be applied also as a gene therapy method in which a normal gene is implanted into a diseased cell of a patient. In this method, the normal inventive protein gene is transfected into the cell which is exogenous or endogenous to the patient and which can be cultured. Then, the transfected cell is infused serologically into a target tissue.

Ideally, the production of an inventive protein by all technologies for the gene therapy gives an intracellular level of the inventive protein which is at least equal to a normal intracellular level of the inventive protein in a non-diseased cell.

As an example, an inventive expression promoting method in the case where the mammalian animal is a transformed mouse is detailed below.

A method for introducing a DNA encoding an inventive protein in the production of a transformed mouse may for example be a microinjection method, a method employing a retrovirus, a method employing an embryonic stem cell (ES cell) and the like. Among those listed above, the microinjection method is employed most frequently. The microinjection method employs a micromanipulator to infuse a solution containing the relevant DNA into the pronucleus of a fertilized ovum under the observation by a microscope.

First, a DNA encoding an inventive protein is infused into a fertilized ovum. In this step, it is preferably to remove the vector region employed for isolating this DNA as much as possible, to remove an AU-rich region contributing to the instabilization of a mRNA and to make the DNA linear for the purpose of integrating the DNA into a chromosome at a high probability. It is also preferable to insert an intron previously into the DNA, and such an intron may for example be a β-globin intron and the like.

A fertilized ovum is obtained from a mouse of a line suitable for the purpose. An inbred C57BL/6 mouse or C3H mouse, a cross line of the C57BL/6 mouse with another line (such as (C57BL/6×DBA/2) F1), a non-inbred line ICR mouse may be exemplified. The fertilized ovum is obtained by mating a female mouse whose superovulation is induced by intraperitoneal administration of both of a pregnant mare's serum gonadotropin and chorionic gonadotropin with a male mouse followed by isolating the ovum from this female mouse. The isolated fertilized ovum is placed in a culture drop, which is maintained in a CO₂ gas incubator, whereby enabling the storage until the infusion of the relevant DNA.

The infusion of the DNA is conducted under the observation with an inverted microscope fitted with a micromanipulator. A fertilized ovum employed is preferably one in a developmental stage of the time when the male pronucleus becomes larger than the female pronucleus through the time when the both pronuclei are fused with each other. First, the fertilized ovum is fixed, and a DNA solution containing the relevant DNA is infused into the male pronucleus of the fertilized ovum. This DNA solution can be prepared as a complex if necessary. A substance used for forming a complex may for example be a liposome, calcium phosphate, retrovirus and the like. The infusion of the DNA solution is evident from the swelling of the male pronucleus. The amount of the DNA infused may for example be an amount containing about 200 to about 3,000 copies of the relevant DNA.

A fertilized ovum into which a DNA encoding an inventive protein has been infused is then cultured as described above until it becomes a blastocyst, which is then implanted into the uterus of a surrogate mother. Preferably, the ovum is implanted into the oviduct of the surrogate mother immediately after the infusion of the DNA. The surrogate mother is preferably a female mouse in a pseudo-pregnant female mouse after mating with a male mouse whose seminal duct has been ligated. Typically, the relevant female mouse is excised at the back skin and muscle near the kidneys to take the ovaries, oviducts and uterus out, and the ovarian membrane is opened to search for the oviduct opening. Then a surviving fertilized ovum after infusing the relevant DNA is imported from the oviduct opening, and then the ovaries, oviducts and uterus are returned into the abdominal cavity, and then the muscle coats are sutured and the skin is clipped. After about 20 days, a neonate is born.

A part of the somatic tissue of the neonate thus obtained, such as a part of the tail, is cut out as a sample, from which DNAs are extracted and subjected for example to a southern blotting, whereby identifying the relevant DNA. As described above, it can be verified that the relevant DNA has been introduced into a non-human animal. Otherwise, a PCR may also be employed for identification.

While a DNA encoding an inventive protein as an active ingredient of an inventive gene therapy agent may be prepared as described above, it can be employed in the form of a recombinant vector or recombinant virus containing the relevant DNA. Such a form may for example be a virus vector such as a retrovirus vector, adenovirus vector, adeno-associated virus vector, herpes simplex virus vector, SV40 vector, polyoma virus vector, papilloma virus vector, picornavirus vector and vaccinia virus vector and the like. When an adenovirus vector is employed, an AdEasy Kit produced by QUANTUM is employed to integrate an inventive DNA into a multiple cloning site of a Transfer Vector, and the resultant recombinant vector is made linear, and then transformed into a coliform microorganism together with a pAdEasy vector, and a homologous recombinant DNA is integrated into a human 293A cell, whereby producing a recombinant virus containing the inventive DNA, which is then recovered and used.

It is also possible to use a non-viral vector such as a plasmid DNA comprising a human cytomegalovirus promoter region. Similarly to a case where an inventive DNA is infused directly into a fibrotic tissue site, a use of a plasmid DNA is extremely beneficial in a system where the inventive DNA is delivered locally using a non-viral vector. By employing a method in which a cell once taken out of a body is introduced with an expression vector and then returned to the body, i.e., an ex vivo method, all of the known introduction methods can be utilized. For example, a non-viral vector can be introduced by means of a) direct infusion, b) liposome-mediated introduction, c) cell transfection by calcium phosphate method, electroporation and DEAE-dextran method, d) polybrene-mediated delivery, e) protoplast fusion, f) microinjection, g) introduction using polylysine and the like.

An inventive gene therapy agent can be given at an effective dose parenterally to a mammalian animal such as a human. For example, a parenteral administration can be accomplished for example by an injection (subcutaneous, intravenosu) as described above. A suitable dosage form described above can be produced by incorporating an inventive DNA (including vector form, virus form, plasmid form of the inventive DNA) into a pharmaceutically acceptable carrier such as an aqueous solvent, non-aqueous solvent, buffering agent, solubilizing aid, osmotic agent, stabilizer and the like. If necessary, auxiliary agents such as a preservative, suspending agent, emulsifier and the like may also be added.

While the dose may vary depending on the age, sex, body weight of a mammalian animal to be treated, the type of an inventive fat accumulation inhibitor, and the dosage form, it is usually an amount of an active ingredient which gives an intracellular level of an inventive protein which is equal to a level allowing the inventive protein to act effectively in the cell of the patient. The daily dose described above may be given all at once or in portions.

Furthermore, the present invention provides a nucleic acid consisting of the entire of or a part of the antisense chain of a DNA encoding an inventive protein or an RNA corresponding thereto. For example, a pathological section is subjected to an in situ hybridization of the DNA encoding the inventive protein, whereby detecting the presence or the stage of a disease.

When an inventive nucleic acid is employed as a diagnostic probe, it may not particularly be limited as long as it has a length of 20 nucleotides or more. For employing such a probe as an active ingredient of a diagnostic agent, the probe is dissolved preferably in a suitable buffer solution or sterilized water in which it is not decomposed. An in situ hybridization may be conducted for example by a method described in J. Neurobiol. 29, 1–17 (1996). It is also possible to employ a PCR method.

EXAMPLES

The present invention is further described in the following Examples, which are not intended to restrict the invention.

Example 1 Acquisition of Inventive DNA and Production of Inventive Vector

Each polynucleotide consisting of the nucleotide sequence represented by any one of SEQ ID NOs: 7 to 10 was synthesized using a DNA synthesizer (Applied Biosystems, Model 394). As a template, 10 ng of a human fetal brain cDNA library (#10662-013 Gibco BRL), a mouse brain cDNA library (#10655-017, Gibco BRL) or a rat brain cDNA library (#9539, Takara) was employed, and each template was combined as shown in Table 1 with the polynucleotide described above as a primer, and subjected to the PCR.

TABLE 1 Combination Forward primer Reverse primer 1 SEQ ID NO: 7 SEQ ID NO: 9 2 SEQ ID NO: 8 SEQ ID NO: 10 3 SEQ ID NO: 7 SEQ ID NO: 10 4 SEQ ID NO: 8 SEQ ID NO: 9

In this PCR, each 10 pmol of the polynucleotide described above was added to 50 μl of the reaction solution, and an LA-Taq polymerase (Takara) and a buffer attached to this enzyme were employed. The reaction solution was incubated using a PCR system 9700 (Applied Biosystems) and subjected to 35 cycles, each cycle consisting of an incubation for 1 minutes at 95° C. followed by 3 minutes at 68° C. Then, the entire volume of the reaction solution was subjected to an agarose gel electrophoresis using a low melting point agarose (agarose L, Nippon Gene). After identifying a single band of an about 2.5 kb DNA, this DNA was recovered. A part of the DNA recovered was used together with a dye terminator sequence kit FS (Applied Biosystems) to prepare a direct sequencing sample, which was subjected to a direct nucleotide sequencing using an autosequencer (Applied Biosystems, Model 3700). The DNA obtained using the human cDNA as a template had the nucleotide sequence represented by SEQ ID NO:4, and this nucleotide sequence encoded the amino acid sequence represented by SEQ ID NO:1. The DNA obtained using the mouse cDNA as a template had the nucleotide sequence represented by SEQ ID NO:5, and this nucleotide sequence encoded the amino acid sequence represented by SEQ ID NO:2. The DNA obtained using the rat cDNA as a template had the nucleotide sequence represented by SEQ ID NO:6, and this nucleotide sequence encoded the amino acid sequence represented by SEQ ID NO:3.

Subsequently, about 1 μg of the about 2.5 kb DNA which was recovered as described above and whose nucleotide sequence was identified was mixed with 10 ng of a pGEM T easy vector (Promega), and combined with a T4 DNA ligase to effect a reaction. The resultant reaction solution was employed to transform an E. coli DH5a competent cell (TOYOBO), and a plasmid DNA was prepared from an ampicillin resistant colony, and its nucleotide sequence was determined using an ABI Model 3700 autosequencer by a dye terminator method. The determined nucleotide sequence was compared with the nucleotide sequence obtained by the direct sequencing described above, and a plasmid whose nucleotide sequence in the translation region exhibited a complete agreement was selected. A plasmid containing a DNA encoding the amino acid represented by SEQ ID NO:1 was designated as pGEM-hNXF, a plasmid containing a DNA encoding the amino acid represented by SEQ ID NO:2 as pGEM-mNXF and a plasmid containing a DNA encoding the amino acid represented by SEQ ID NO:3 as pGEM-rNXF.

The amino acid sequence represented by SEQ ID NO:1, 2 or 3 was compared with each other using a GenetyxSV/R ver.4 program (SOFTWARE KAIHATSU). As a result, the amino acid homology between the amino acid sequence represented by SEQ ID NO:1 and the amino acid sequence represented by SEQ ID NO:2 was 93%, and the amino acid homology between the amino acid sequence represented by SEQ ID NO:2 and the amino acid sequence represented by SEQ ID NO:3 was 98%.

The amino acid sequence represented by SEQ ID NO:1, 2 or 3 was subjected to a motif search by utilizing the database service by GenomNet referring to each of the motif dictionaries including PROSITE (Nucl. Acids. Res, 1997; 24:217–221, Bairoch, A. et al.), BLOCKS (Nucl. Acids. Res, 1991; 19:6565–6572, Henikoff, S. et al.), ProDom (Protein Sci, 1994; 3:482–492, Sonnhammer, E. L. et al.) and PRINTS (Protein Eng, 1994; 7:841–848, Attwood, T. K. et al.). As a result, any of the amino acid sequences had a bHLH motif in a region around the amino acid Nos.1 to 24 and a PAS domain in a region around the amino acid Nos.25 to 310.

Example 2 Amplification of cDNA Encoding Inventive Protein by PCR

A cDNA prepared from a mRNA extracted from a pooled reticulum of 76 humans (#7124-1, Clontech) was employed as a template to perform a PCR using the polynucleotide oligonucleotide comprising the nucleotide sequence represented by SEQ ID NO:52 and the polynucleotide oligonucleotide comprising the nucleotide sequence represented by SEQ ID NO:53 as primers. Each 10 pmol of the polynucleotide described above was added to 50 μl of the reaction solution, and an LA-Taq polymerase (Takara) and a buffer attached to this enzyme were employed. The reaction solution was incubated using a PCR system 9700 (Applied Biosystems) and subjected to 35 cycles, each cycle consisting of an incubation for 1 minutes at 95° C. followed by 3 minutes at 68° C. Then, the entire volume of the reaction solution was subjected to an agarose gel electrophoresis using an agarose (agarose S, Nippon Gene). A single band of the DNA was observed at about 2.5 kb. It was thus verified that the mRNA encoding the inventive protein was expressed in the human reticulum.

Example 3 Detection of Nucleic Acid Encoding Inventive Protein by Hybridization

The plasmid pGEM-hNXF prepared in EXAMPLE 1 was digested with BamHI and NotI, and the digestion product was subjected to an agarose gel electrophoresis using a low melting point agarose (agarose L, Nippon Gene) to recover an about 1.0 kbp DNA and an about 2.3 kbp DNA. 50 ng of each DNA thus recovered was ³²P-labeled using a labeling kit by a random primer method (Rediprime II: Amersham Pharmacia) and α³²P-dCTP (Amersham Pharmacia).

Using the about 1.0 kbp labeled DNA as a probe, a hybridization was performed with nylon filters blotted with mRNAs of various human tissues [Human 12-Lane MTN Blot (#7780-1, Clontech) and Human MTN Blot IV (#7766-1 Clontech)]. On the other hand, the about 2.3 kbp labeled DNA was used as a probe to perform a hybridization with nylon filters blotted with mRNAs of human tissues such as a brain [Human Brain MTN Blot II (#7755-1, Clontech) and Human Brain MTN Blot IV (#7769-1 Clontech)].

The hybridization conditions were in accordance with the manufacturer's instruction of the nylon filters described above. Thus, the nylon filter was incubated in 5 ml of an ExpressHyb solution (Clontech) at 68° C. for 30 minutes, and 50 ng of each labeled probe described above was added and the incubation was continued for 1 hour at 68° C. Then the filter was subjected twice to the incubation at 65° C. for 30 minutes in about 200 ml of 2×SSC containing 0.05 DS, and then further subjected twice to the incubation at 65° C. for 30 minutes in 0.1×SSC containing 0.1% SDS. Subsequently, the nylon filter was brought into a close contact with an imaging plate (FUJI FILM) and allowed to stand for 1 weeks, and then subjected to an imaging analyzer (BASstation: FUJI FILM) to detect the sensitized image on the plate. The investigated human tissues are as shown below.

Brain, Heart, Skeletal muscle, Colon (no mucosa), Thymus, Spleen, Kidney, Liver, Small intestine, Placenta, Lung, Peripheral blood leukocyte, Prostate, Testis, Uterus (no endometrium), Cerebellum, Cerebral cortex, Medulla, Spinal cord, Occipital pole, Frontal lobe, Temporal lobe, Putamen, Amygdala, Caudate nucleus, Corpus callosum, Hippocampus, Substantia nigra, Thalamus.

As a result, the nylon filters blotted with the mRNAs of various human tissues exhibited an intense signal at the brain, low signals at the skeletal muscle and kidney, and no signals at other tissues. On the other hand, the nylon filters blotted with mRNAs of human tissues such as a brain exhibited signals at all brain tissues, medulla and spinal cord blotted on the filters.

Example 4 Genotype Analysis of Gene Encoding Inventive Protein

0.1 gram of a frozen human brain sample is combined with 1 ml of a Trizole reagent (Gibco BRL) and homogenized. The resultant homogenate is combined with 0.2 m 1 of chloroform, stirred, centrifuged at 4° C. and 12000×g for 15 minutes, and the organic layer and the aqueous layer are transferred into separate tubes. The aqueous layer is combined with 0.5 ml of isopropanol, mixed, allowed to stand at room temperature for 5 minutes, centrifuged at 4° C. and 12000×g for 10 minutes, and the precipitated RNA is recovered. The recovered precipitate is rinsed with 70% ethanol, air-dried, dissolved in water, and used as a human RNA sample.

Using 1 μg of the human brain RNA thus prepared as a template and 1 μg of oligo dT primer (Amersham Pharmacia) as a primer, an incubation is conducted at 37° C. for 1 hour in the presence of Superscript II (Gibco) and a buffer attached to this enzyme. A 1/50 volume of the resultant human brain cDNA solution is employed as a template to perform a PCR similarly to EXAMPLE 1 using the polynucleotide consisting of the nucleotide sequence represented by SEQ ID NO:7 and the polynucleotide consisting of the nucleotide sequence represented by SEQ ID NO:9 as primers, whereby amplifying the DNA. The resultant DNA is subjected to an agarose gel electrophoresis using a 1% low melting point agarose (agarose L, Nippon Gene) and recovered. The entire amount of the recovered DNA is used as a template to prepare a sample for a direct sequencing by a dye terminator sequence kit FS (Applied Biosystems). Then the sample is subjected to a nucleotide sequencing using an autosequencer (Applied Biosystems, Model 3700) to determine the nucleotide sequence.

On the other hand, 0.1 g of a human liver frozen sample was combined with the Trizole reagent and the organic layer was isolated as described above. The resultant organic layer was combined with 0.3 ml of ethanol, centrifuged at 4° C. and 2000×g for 5 minutes to recover the precipitate. This precipitate was rinsed with a mixture of 0.1M sodium citrate and 10% ethanol, air-dried, dissolved in TE, whereby obtaining a human genomic DNA sample. This human genomic DNA was employed as a template to perform a PCR, whereby amplifying the nucleotide sequence of the exon of the genome gene encoding an inventive protein and the DNA containing a part of the nucleotide sequence of the intron adjacent to this exon. As a primer, the polynucleotide consisting of the nucleotide sequence represented by any of the SEQ ID NOs:11 to 42 was prepared by DNA synthesizer (Applied Biosystems, Model 394), and employed in the combinations shown in Table 2.

TABLE 2 Sample No. Forward primer Reverse primer  1 SEQ ID NO: 11 SEQ ID NO: 13  2 SEQ ID NO: 12 SEQ ID NO: 14  3 SEQ ID NO: 15 SEQ ID NO: 17  4 SEQ ID NO: 16 SEQ ID NO: 18  5 SEQ ID NO: 19 SEQ ID NO: 21  6 SEQ ID NO: 20 SEQ ID NO: 22  7 SEQ ID NO: 23 SEQ ID NO: 25  8 SEQ ID NO: 24 SEQ ID NO: 26  9 SEQ ID NO: 27 SEQ ID NO: 29 10 SEQ ID NO: 28 SEQ ID NO: 30 11 SEQ ID NO: 31 SEQ ID NO: 33 12 SEQ ID NO: 32 SEQ ID NO: 34 13 SEQ ID NO: 35 SEQ ID NO: 37 14 SEQ ID NO: 36 SEQ ID NO: 38 15 SEQ ID NO: 39 SEQ ID NO: 41 16 SEQ ID NO: 40 SEQ ID NO: 42

The PCR was conducted using a LA-Taq DNA polymerase (Takara) in a buffer attached specially with the enzyme described above in the presence of 100 μM of each of the 4 nucleotides (dATP, dTTP, dGTP, dCTP), which was subjected to 35 cycles, each cycle involving an incubation at 95° C. for 1 minutes followed by 68° C. for 1 minute. A part of each resultant reaction solution was subjected to an agarose gel electrophoresis. Any of the sample Nos. 1 to 16, a single DNA band was detected on the agarose gel.

The remaining PCR reaction solution is run on a 1% low melting point agarose (agarose L, Nippon Gene) and the DNA detected as a band is recovered. The recovered DNA is used as a template to prepare a sample for a direct sequencing by a dye terminator sequence kit FS (Applied Biosystems). Then the sample is subjected to a nucleotide sequencing using an autosequencer (Applied Biosystems, Model 3700) to determine the nucleotide sequence.

2 or 3 hairs are washed with a sterilized water and then with 100% ethanol, dried at room temperature, cut into 2 to 3 mm pieces, which are transferred to a plastic tube. To this, 200 μl of a BCL-Buffer [10 mM Tris-HCl (pH7.5), 5 mM MgCl₂, 0.32 sucrose, 1 Triton X-100] is added, followed by a Proteinase K at the final concentration of 100 μl/ml and SDS at the final concentration of 0.5 (w/v). The mixture thus obtained is incubated at 70° C. for 1 hour, combined with an equal volume of phenol/chloroform, shaken vigorously, and centrifuged (15000 rpm, 5 minutes, 4° C.). The aqueous layer is recovered by pipetting carefully to avoid any disturbance to the phenol layer, and then extracted again with phenol. The recovered aqueous layer is combined with an equal volume of chloroform, shaken vigorously, and centrifuged to recover the aqueous layer. The recovered aqueous layer is combined with 500 μl of 100% ethanol, kept at −80° C. for 20 minutes, and then centrifuged. The resultant pellet is dried, dissolved in a sterilized water, and used as a genomic DNA, which is subjected to a PCR as described above. When a human peripheral blood is employed as a sample, 10 ml of the blood is taken and the genomic DNA is extracted using a DNA-Extraction kit (Stratagene) in accordance with the attached manual. The resultant genomic DNA is subjected to a PCR as described above.

Example 5 Analysis of Genotype by PCR-SSCP

The polynucleotide employed as a primer in EXAMPLE 4 is labeled at its terminal with ³²p using a DNA MEGALABEL Kit (Takara). About 1 μg of a genomic DNA obtained similarly to EXAMPLE 4 is used as a template together with each about 100 pmol of the labeled polynucleotide as a primer to conduct a PCR to amplify the DNA of the genome gene encoding an inventive protein. This PCR is conducted using a LA-Taq DNA polymerase (Takara) in a buffer attached specially with the enzyme described above in the presence of 100 μM of each of the 4 nucleotides (dATP, dTTP, dGTP, dCTP), which is subjected to 35 cycles, each cycle involving an incubation at 95° C. for 1 minutes followed by 68° C. for 1 minute. A 1/20 volume of the amplified DNA is denatured by heating in a 80% formamide at 80° C. for 5 minutes, and the 1/20 volume of this is subjected to an electrophoresis in 180 mM tris-borate buffer solution (pH8.0) on a 5% non-modified neutral polyacrylamide gel. The electrophoresis conditions involves room temperature, air cooling, constant power 40 W for 60 minutes. After completing the running, the gel is brought into a close contact with an X-ray film to obtain an autoradiogram, whereby detecting the DNA which had been amplified using the labeled polynucleotides as primers. The DNA encoding the relevant region of a standard protein is also run in parallel, whereby comparing with the mobility of the DNA derived from the sample. When the mobility of the these DNAs is different from each other, then the nucleotide sequence encoding the inventive protein in the nucleic acid in the test sample is judged to contain the nucleotide sequence encoding the amino acid sequence which is different from the amino acid sequence of the standard protein. Then, the part of the gel in the position corresponding to the band of the DNA derived from the test sample detected by an autoradiography is cut into a 1 mm×1 mm square piece, which is treated in 100 μl of a sterilized water at 90° C. for 10 minutes, a 1/20 volume of which is then used as a template to perform a PCR. The amplified DNA is subjected to an electrophoresis on a low melting point agarose gel and the DNA is recovered from the gel, and the recovered DNA is used as a template to perform a nucleotide sequencing using a BigDye Terminator cycle sequence ready reaction kit (Applied Biosystems) and an automatic DNA sequencer (Applied Biosystems, Model 377), whereby characterizing any variation.

Example 6 Transcriptional Regulation Ability of Inventive Protein

(6-1) pGL3-TATA-Galx Preparation

A pGL3-TATA-Calx4, which is the reporter gene plasmid employed for measuring the transcription regulation ability of a fusion protein between the GAL4 DNA binding region and any transcription regulatory factor, is one formed by introducing, into the upstream of the luciferase gene comprising a TATA minimum promoter, 4 copies in tandem of a DNA to which the GAL4 DNA binding region can be bound. By measuring the expression level of the luciferase in the case that the fusion protein between the GAL4 DNA binding region and any transcriptional regulation factor exerts its effect on the reporter gene plasmid described above, the transcription regulation ability possessed by this fusion protein can applicably be measured. This pGL3-TATA-Galx4 reporter gene plasmid was prepared as described below.

First, two oligonucleotides each comprising a DNA to which the GAL4 DNA binding region can be bound (5′-cgcgtcgagc tcgggtcgga ggactgtcct ccgactgctc gagtcgagct cgggtcggag gactgtcctc cgactgctcg aga-3′ (SEQ ID NO:56), 5′-cgcgtctcga gcagtcggag gacagtcctc cgacccgagc tcgactcgag cagtcggagg acagtcctcc gacccgagct cga-3′ (SEQ ID NO:57)) were hybridized, and phosphorylated at the 5′ terminal using a T4 kinase, and then bound in tandem using a T4 ligase. The resultant double-stranded oligonucleotide was subjected to an electrophoresis using a low melting point agarose (NuseiveGTG; FMCbio) to recover a DNA fragment in which these double stranded oligonucleotide are bound in tandem. This was used as an insert fragment, which was reacted with 0.1 μg of the pGL3-TATA vector, which had been cleaved with MluI and then treated with an alkaline phosphatase (BAP C75; Takara) in the presence of a T4 Ligase (Takara) at 16° C. for 16 hours, whereby effecting the binding. As a result, a pGL3-TATA-Calx4, which is the reporter gene plasmid formed by introducing, into the upstream of the luciferase gene comprising a TATA minimum promoter, 4 copies in tandem of the DNA to which the GAL4 DNA binding region can be bound, was obtained.

(6-2) pRC/RSV-Gal4-DBD Preparation

On the other hand, a pRC/RSV-Gal4-DBD which is a plasmid expressing only the GAL4 DNA binding region (i.e., Gal4-DBD, a part lacking the transcriptional control region) was prepared as described below.

A pM which is a plasmid comprising a Gal4-DBD (contained in a commercial kit K1602-1; Clontech) was cleaved with NheI and XbaI, and then made blunt-ended using a T4 polymerase. This was subjected to an electrophoresis on a low melting point agarose (agarose L; Nippon Gene) to recover a DNA fragment (about 500 bp) encoding a Gal4-DBD. The recovered DNA fragment was employed as an insert fragment.

Then, a pRC/RVS (Invitrogen) was cleaved with HindIII, and made blunt-ended using a T4 polymerase. This was BAP-treated and used as a vector, and this vector (0.1 μg) was ligated with the insert fragment (0.5 μg) described above using a T4 ligase, whereby obtaining a pRC/RSV-Gal4-DBD (thus, Gal4 DBD). The correct construction of the plasmid for expressing the Gal4-DBD under the control of the RSV promoter was verified using an ABI Model 3700 autosequencer to determine the nucleotide sequence by a dye terminator method.

(6-3) pRC/RSV-MA Preparation

In order to express a fusion protein in which a GAL4 DNA binding region has been bound for example to a transcription regulation region of any transcription regulatory factor, a pRC/RSV-MA in which the recognition site of PmaCI which is a restriction enzyme capable of giving a blunt end has been introduced to the downstream of the Gal4-DBD was prepared. This plasmid has a translation region of a DNA encoding the Gal4-DBD downstream of the RSV promoter, and can be bound, at a further downstream PmaCI cleavage blunt end, with a blunt-ended DNA fragment in such a manner that the translation frame of the DNA encoding the Gal4-DBD is in agreement with the translation frame of the blunt-ended DNA fragment. As a result, the fusion protein in which a GAL4 DNA binding region has been bound for example to a transcription regulation region of any transcription regulatory factor can be expressed.

Typically, the pRC/RSV-MA was prepared as described below.

First, two oligonucleotides (5′-agcttcatcccacgtgagtcat-3′,5′-ctagatgactcacgtgggatga-3′) were hybridized and then phosphorylated at the 5′ terminal using a T4 kinase. This was used as an insert fragment and the pRC/RSV-Gal4-DBD prepared in Section (6-2) described above was used as a vector after the cleavage with HindIII 29dand XbaI followed by the BAP treatment, and the both were bound using a T4 ligase, whereby obtaining a pRC/RSV-MA.

(6-4) Preparation of pRC/RSV-MA-mNXF(AvaI frg)

A pRC/RSV-MA-mNXF (AvaI frg) which is a plasmid for expressing a fusion protein between a GAL4 DNA binding region (i.e., GAL4-DBD) and the transcription regulation region of an inventive protein (hereinafter this plasmid being sometimes referred to as Gal4-NXF Cterm) was prepared as described below.

First, the pGEM-mNXF prepared in EXAMPLE 1 was cleaved with avaI and NotI, and then made blunt-ended using a T4 polymerase. This was subjected to a low melting point agarose gel electrophoresis (agarose L; Nippon Gene) to recover a DNA fragment (about 1.8 kbp). The recovered DNA fragment was a DNA fragment encoding the transcription regulation region from the inventive protein bHLH motif-PAS domain to the C terminal. This recovered DNA fragment was used as an insert fragment and the pRC/RSV-MA prepared in Section (6-3) described above was used as a vector after the cleavage with PmaCI restriction enzyme followed by the BAP treatment, and the both were bound using a T4 ligase, whereby obtaining a pRC/RSV-MA-mNXF (Aval frag). The correct direction of the binding of the insert fragment and the agreement of the translation frames in the binding region were verified using an ABI Model 3700 autosequencer to determine the nucleotide sequence by a dye terminator method.

Then, about 1×10⁷ cells of a neuroblastoma IMR32 (ATCC No.CCL127; purchased from DAINIPPON SEIYAKU) were cultured in a 10% FBS-supplemented DMEM medium (NISSUI SEIYAKU) at 37° C. in the presence of 5% CO² in a petri dish (Falcon) whose diameter was about 10 cm. On the next day, the cultured cells were dispersed by a trypsin treatment, washed twice with a FBS-free DMEM medium, and then dispersed again in a FBS-free DMEM medium at the cell density of 1×10⁷. 0.4 ml of this cell dispersion was combined with each 3 μg of the two plasmids prepared in Sections (6-2) and (6-3) described above, namely, pRC/RSV-Gal4-DBD and pRC/RSV-MA-mNXF (AvaI frag), and the mixture was transferred into an electroporation cuvette, where a transfection was conducted by an electroporation method employing a Gene pulser (BIORAD) under the conditions involving 200V and 950 μF. After the transfection, the culture medium was replaced with a 10% FBS-supplemented DMEM, and then further cultured in a 6-well plate for about 24 hours. Then, the culture medium was removed from the wells, and the cells depositing on the plate wall were washed twice with PBS(−), and then 200 μl per well of a 5-fold diluted PGC 50 (TOYO INK) was added and allowed to stand at room temperature for 30 minutes. 20 μl Aliquots of this cell suspension were dispensed into a opaque plate (Coning Coaster Co., Ltd.), and this plate was mounted on a luminometer LB96P (Berthold, co. ltd) fitted with an enzyme substrate automatic injector, and after dispensing 20 μl of the substrate solution PGL100 (TOYO INK) automatically the luciferase activity of each well was determined.

The results are shown in FIG. 1. As evident from FIG. 1, the one hybrid assay employing the reporter gene plasmid pGL3-TATA-Galx4 revealed a high level expression of the reporter gene in a transformant (designated as Gal4-NXF Cterm in Figure) expressing the fusion protein in which the GAL4 DNA binding region has been bound to the transcription regulation region (AvaI site to C terminal) of the inventive protein. On the other hand, the control transformant expressing only the Gal4 DNA binding region (designated as Gal4 DBD in Figure) exhibited no reporter gene expression. Thus, in the case employing as a host cell a neuroblastoma such as an IMR32, the inventive protein was proven to have a transcription activating ability as a transcription regulation ability.

(6-5) Preparation of pGL3-TATA Vector

The pGL3-TATA vector employed for constructing the pGL3-TATA-Galx4 in Examples described above was prepared as described below.

First, two oligonucleotides consisting of a nucleotide sequence near the TATA box of a mouse metallothionein I gene and the nucleotide sequence derived from a reader sequence (Genbank Accession No. J00605) (5′-GATCTCGACTATAAAGAGGGCAGGCTGTCCTCTAAGCGTCACCACGACTTCA-3′ (SEQ ID NO:58), 5′-AGCTTGAAGTCGTGGTGACGCTTAGAGGAC AGCCTGCCCTCTTTATAGTCGA-3′ (SEQ ID NO:59)) were hybridized and phosphorylated at the 5′ terminal using a T4 kinase (this DNA is sometimes designated as TATA DNA). 1 μg of this TATA DNA was used as an insert fragment and was ligated (16° C., reaction for 16 hours) to a firefly luciferase gene-containing vector plasmid pGL3 (Promega) after a digestion with restriction enzymes BglII and HindIII followed by a treatment with the alkaline phosphatase (BAP C75; Takara) (0.1 μg) using a T4 Ligase (Takara), whereby obtaining a pGL3-TATA.

Example 7 Screening for Substance Altering Transcription Regulation Ability of Inventive Protein

An animal cell expression pM vector (Clontech) is digested with SmaI and incubated in the presence of an alkaline phosphatase (BAP) for 1 hour at 65° C., and then subjected to a low melting point agarose gel electrophoresis to recover a vector DNA. On the other hand, the pGEM-hNXF prepared in EXAMPLE 1 is digested with NcoI and NotI, made blunt-ended using a Blunting Kit (Takara), subjected to a low melting point agarose gel electrophoresis to recover an about 2 kb DNA. The recovered vector DNA described above is mixed with the about 2 kb DNA and reacted with a L4 ligase. This reaction mixture is introduced into an E. coli DH5α competent cell (TOYOBO). The resultant E. coli transformant is cultured and its plasmid is extracted, and the plasmid thus obtained is subjected to a restriction enzyme analysis and a nucleotide sequencing. A plasmid resulting from the insertion of the about 2 kb DNA described above into a pM vector is selected and designated as pM-hNXF (SmaI). As a result, a vector for expressing a fusion protein between the GAL4 DNA binding region and a polypeptide comprising a partial amino acid sequence of the inventive protein is obtained.

About 2×10⁶ Hela cells are inoculated onto a 10-cm plate and cultured in an FBS-supplemented E-MEM medium in the presence of 50₂ at 37° C. for one day. To the cells thus obtained, 3.75 μg of the plasmid pM-hNXF (SmaI) and 3.75 μg of the plasmid pFR-LUC (Stratagene; containing a Gal4-responsive luciferase gene) are introduced using a lipofectamine (Life Technologies) in accordance with the attached protocol. After culturing at 37° C. for 16 hours, the medium is replaced and the culture is continued further for 3 hours. The cells are harvested, suspended uniformly in an FBS-supplemented E-MEM medium, and then inoculated into a 96-well plate to which the culture medium containing any of various test substances dissolved in DMSO at a varying concentration had been added (final concentration of DMSO: 0.1). This plate is cultured at 37° C. for about 40 hours, received 50 μl/well of a 5-fold diluted cell solubilizer PGC50 (Nippon Gene), and allowed to stand at room temperature for 30 minutes with an intermittent gentle shaking to effect the cell dissolution. The cell solution thus obtained is dispensed in 10 μl aliquots into a 96-well white sample plate (Berthold, co. ltd), and examined immediately for the luminescence over a period of 5 seconds using a luminometer LB96p (Berthold, co. ltd) fitted with an automatic substrate injector while adding 50 μl/well of the enzyme substrate solution PGL100 (Nippon Gene).

Example 8 Acquisition of Genomic DNA Encoding Inventive Protein

The plasmid pGEM-mNXF obtained in EXAMPLE 1 was digested with EcoRI and HindIII and subjected to an agarose gel electrophoresis using a low melting point agarose (agarose L, Nippon Gene) to recover an about 0.6 kb DNA, 0.9 kb DBA and 1 kb DNA. Equal amounts of the recovered DNAs were combined, and an about 25 ng aliquot was taken and labeled with ³²p using an Amersham Multiprime DNA labeling system in accordance with the protocol attached to this system.

An E. coli XL1-Blue MRA (Stratagene) was cultured overnight and 0.3 ml of the resultant culture medium was combined with a mouse (129SvJ line) genomic DNA library (#946313m Stratagene) in such an amount that 5×10⁴ plaques were formed per plate whose diameter was 15 cm, incubated at 37° C. for 20 minutes, and then immediately after adding 6.5 ml of a 0.7 agarose which had been kept at 50° C., and it was spread over a NZYM (10 g of Nzamine, 5 g of NaCl, 5 g of yeast extract, 2 g of MgSO₄.7H₂O and 5 g of agar dissolved in 1 L of water) whose diameter was 15 cm.

This plate was incubated at 37° C. overnight. Then the surface of the plate on which the plaques were formed was covered gently with a round nitrocellulose filter (Hybond N; Amersham) whose diameter was 15 cm, to which the plaques were transferred. This filter was allowed to stand at room temperature for 20 minutes, and then mounted for 5 minutes on a filter paper which had been immersed in a denaturing buffer (composition: 0.2N, NaOH, 1.5M NaCl). Subsequently, this filter was mounted for 1 minutes on a filter paper which had been immersed in a neutral buffer (composition: 0.4M Tris-HCl, pH7,5, 2×SSC), and then immersed in 500 ml of 2×SSC for 5 minutes. Then the filter was transferred onto a dry filter paper, allowed to stand at room temperature for several hours for drying, and then kept in an oven at 80° C. for 2 hours. The resultant filter was placed in a plastic seal bag, and incubated overnight at 65° C. in 50 ml of a hybrid buffer (composition: 5×SSC, 5 mM HEPES, pH7.0, 10× Denhart's solution, 20 μg/ml denatured salmon sperm DNA). Then it was combined with the entire amount of the ³²P-labeled DNA described above which had been denatured by heating, and then incubated at 65° C. overnight. Then the filter was taken out and rinsed in 2×SSC at room temperature for 30 minutes, and then rinsed in 0.1×SSC at 65° C. for 40 minutes. The filter was then transferred into a fresh 0.1×SSC, rinsed at 65° C. for 40 minutes, allowed to stand on a filter paper at room temperature for drying, and subjected to an autoradiography (at −80° C. for 2 days).

A phage was recovered from a plate corresponding a part which exhibited a positive signal in the autoradiography described above, and suspended in 100 μl of an SM buffer (5.8 g of NaCl, 2 g of MgSO₄.7H₂O and 0.1 g of gelatin dissolved in 1 L of water, pH7.5). The resultant phage suspension was employed to perform a secondary screening by a hybridization method in a manner similar to that described above, except that the number of the plaques to be formed per plate was about 1000. A plaque was recovered from a plate corresponding a part which exhibited a positive signal in this screening, subjected to a tertiary screening similarly to the secondary screening, whereby obtaining a phage clone exhibiting the positive signal.

1 μl of the suspension of a phage clone which exhibited the positive signal described above was added to 100 μl of a TE buffer, boiled and employed as a template to perform a PCR. As primers, two primers which anneal to the both sides of the cloning site possessed by a Lambda FIXII vector employed for preparing the genomic DNA library described above [T7 universal primer and T3 universal primer (Stratagene)] were employed. The PCR reaction solution contained 5 μl of the boiling solution described above, each 1 pmol of the two primers described above, LA-taq polymerase (Takara) and a buffer attached to this enzyme in the total volume of 50 μl. The reaction was conducted in 35 cycles, each cycle consisting of an incubation for 1 minutes at 95° C. followed by 1 minutes at 50° C. followed by 10 minutes at 72° C. Subsequently, the reaction solution was subjected to an agarose gel electrophoresis to recover an about 7 kbp DNA. About 10 μg of the recovered DNA was employed as a template to perform a direct sequencing using a Dye Terminator Cycle Sequence FS kit (Perkin Elmer ABI) in accordance with the protocol attached to this kit. As a result, the DNA described above was revealed to comprise the nucleotide sequence represented by SEQ ID NO:54. By comparing the resultant nucleotide sequence with the nucleotide sequence represented by SEQ ID NO:5, the intron/exon structure was clarified.

Example 9 Promotion of Drebrin 1 Expression by Inventive Protein

First, about 1×10⁷ SK-N-MC cells (ATCC No. CHTB10; purchased from DAINIPPON SEIYAKU) were cultured in a 10% FBS-supplemented DMEM medium (NISSUI SEIYAKU) at 37° C. in the presence of 5% CO₂ in a petri dish (Falcon) whose diameter was about 10 cm.

On the next day, the cultured cells were dispersed by a trypsin treatment, washed twice with a FBS-free DMEM medium, and then dispersed again in a FBS-free DMEM medium at the cell density of 1×10⁷. 0.4 ml of this cell dispersion was combined with 10 μg of the plasmids prepared as described above, namely, (a) a pRC/RSV-mNXFsense which is a plasmid expressing the sense strand of the DNA encoding the full-length inventive protein and (b) a pRC/RSV-mNXFantisense which is a plasmid expressing the antisense strand of the DNA encoding the full-length inventive protein downstream of the RVS promoter, and the mixture was transferred into an electroporation cuvette, where a transfection was conducted by an electroporation method employing a Gene pulser (BIORAD) under the conditions involving 200V and 950 μF. After the transfection, the culture medium was replaced with a 10% FBS-supplemented DMEM, and then further cultured in a 10-cm petri dish for about 24 hours. After the culture, (a) 5 dishes of the pRC/RSV-mNXFsense-introduced cell and (b) 5 dishes of the pRC/RSV-mNXFantisense-introduced cell were subjected to the purification of the DNA-free total RNA using a commercial RNA purification and radiolabelling kit, namely, Atlas Pure Total RNA Labeling system (K1038-1; Clontech). The RNA yield was (a) 23 μg and (b) 26 μg. Subsequently, the commercial kit described above and the resultant RNA were employed for radiolabelling each RNA with [α-P³²]-dATP (Amersham Pharmacia) using the specific primers contained in the commercial kit together with the reverse transcriptase. The radiolabeled RNA thus obtained (hereinafter referred to as a probe) was purified using the commercial kit described above, and this purified RNA was adjusted at 1.3×10⁵ DPM, and then used in the hybridization reaction described below. The hybridization reaction was conducted using a commercial kit including a nylon membrane onto which various genes had been blotted (Atlas cDNA Expression array-Neurobiology; 7736-1) together with the attached hybridization buffers. The hybridization conditions involved the reactions of (a) the nylon membrane corresponding to the probe derived from the pRC/RSV-mNXFsense-introduced cell and (b) the nylon membrane corresponding to the probe derived from the pRC/RSV-mNXFantisense-introduced cell, over a period of 18 hours under identical conditions in identical incubators. After the reaction, the nylon membrane was washed with 2×SSC, 1% SDS buffer (68° C., 30 minutes). This procedure was repeated 4 times, and the washing was further conducted in 0.1×SSC, 0.5% SDS buffer (68° C., 30 minutes). Each nylon membrane was wrapped with a plastic film, exposed to an IP plate (FUJI FILM) for 7 days, and then subjected to the quantification and the comparison of the probe hybridization signals corresponding to various genes on the nylon membrane using an imaging analyzer (BASstation, FUJI FILM).

As a result, a significantly more intense signal to the drebrin 1 gene was noted by (a) the hybridization signal on the nylon membrane corresponding to the probe derived from the pRC/RSV-mNXFsense-introduced cell rather than (b) the hybridization signal on the nylon membrane corresponding to the probe derived from the pRC/RSV-mNXFantisense-introduced cell. Thus, the inventive protein was proven to have an ability of promoting the expression of the drebrin 1.

Example 10 Preparation of Reporter Gene Operably Ligated with Expression Regulation Region of DNA Encoding Inventive Protein and Verification of its Promoter Activity: Mouse-Originated Inventive Protein Genome Nucleotide Sequencing

(10-1) Preparation of Materials

The nucleotide sequence of the genome of the inventive protein derived from a mouse represented by SEQ ID NO:55 was determined as described below.

First, for the purpose of amplifying only the FIXII vector insert sequence part of the clone designated as Clone 12 among the genome phage clones of the inventive protein obtained by the screening as described above, a T7 universal primer and a T3 universal primer (Stratagene) which is a primer pair provided on the FIXIII vector were employed together with a LA-Taq polymerase (Takara) and 1 μl of a Clone 12 phage solution to conduct a PCR reaction including 35 cycles, each cycle involving an incubation at 95° C. for 1 minutes followed by 68° C. for 20 minutes. As a result, an amplified DNA fragment (about 21 kbp) was obtained. The resultant amplified DNA fragment was subjected to an electrophoresis on a 0.8% low melting point agarose (agarose L; Nippon Gene), whereby purifying and recovering the DNA fragment. The purified and recovered DNA fragment was subjected to a custom primer direct sequencing using a capillary sequencer (PE-biosystems, Model 3700) and a Dye Terminator Sequence Kit FS ver 2 (PE-biosystems), whereby determining the entire nucleotide sequence (SEQ ID NO:55) of this DNA fragment.

(10-2) Preparation of Reporter Gene Operably Ligated with Expression Regulation Region of DNA Encoding Inventive Protein

In order to obtain the expression regulation region of a DNA encoding an inventive protein containing about 10 kbp, 5 kbp, 2.5 kbp or 1 kbp upstream of the transcription initiation point of the gene of an inventive protein derived from a mouse (nucleotide numbers 9437 to 9442 in the nucleotide sequence of the genome of the inventive protein derived from the mouse), the nucleotide sequence of the genome of the inventive protein represented by SEQ ID NO:55 was utilized to design the forward PCR primer consisting of any of the following nucleotide sequences. About 10 kbp upstream: 5′-gggcggtaccatacctagggccaataggagtgatgagcccatgtc-3′ (SEQ ID NO:60);

About 5 kbp upstream: 5′-gggcggtaccaacgaggaatctctcttcctctccactgtccgggc-3′ (SEQ ID NO:61);

About 2.5 kbp upstream: 5′-gggcggtaccctgcttaaattgcttggagaccagctgtggaccca-3′ (SEQ ID NO:62);

About 1 kbp upstream: 5′-gggcggtaccctcagtgacaagtgcacaggcagaacgaggagccc-3′ (SEQ ID NO:63).

Similarly utilizing the nucleotide sequence of the genome of the inventive protein, a reverse PCR primer comprising the following nucleotide sequence was also designed.

5′-gggcacgcgttcgcctgcctcgatccgccttatgtagctcctgac-3′ (SEQ ID NO:64).

Into the forward primer employed here, a KpnI restriction enzyme site had been introduced, and a MluI restriction enzyme site had been introduced into the reverse primer. Using the forward primer and the reverse primer described above as a primer pair together with 1 μl of the genome phage clone of the inventive protein derived from the mouse as a template, a PCR was conducted using a KODplus polymerase (TOYOBO). The PCR conditions employed 35 cycles, each cycle involving an incubation at 95° C. for 1 minutes followed by 68° C. for 10 minutes. As a result, the expression regulation regions of the DNA encoding the inventive protein containing about 10 kbp, 5 kbp, 2.5 kbp and 1 kbp upstream of the transcription initiation point of the gene of the inventive protein derived from the mouse were amplified. Each of these regions was cleaved simultaneously by both of the restriction enzymes KpnI and MluI, and subjected to a low melting point agarose electrophoresis (agarose L; Nippon Gene) to recover each amplified DNA fragment. Each recovered amplified DNA fragment (about 0.5 μg) was employed as an insert fragment, which was ligated to a pGL3-TATA vector prepared in EXAMPLE 6 which had been cleaved by KpnI and MluI and then treated with an alkaline phosphatase (BAP C75; Takara) (0.1 μg) using a T4 ligase (Takara) (16° C., 16 hours), whereby obtaining the plasmids into which the expression regulation regions of the DNA encoding the inventive protein containing about 10 kbp (nucleotide Nos.72 to 9436 in the nucleotide sequence represented by SEQ ID NO:55), 5 kbp (nucleotide Nos.4364 to 9436 in the nucleotide sequence represented by SEQ ID NO:55), 2.5 kbp (nucleotide Nos.6889 to 9436 in the nucleotide sequence represented by SEQ ID NO:55) and 1 kbp (nucleotide Nos.8216 to 9436 in the nucleotide sequence represented by SEQ ID NO:55) upstream of the transcription initiation point of the gene of the inventive protein derived from the mouse had been inserted into the upstream of the luciferase gene comprising a TATA minimum promoter.

(10-3) Verification of Promoter Activity Possessed by Expression Regulation Region

A pGL3-TK-BSD, which was a control reporter plasmid for investigating the relative activity of the promoter activity possessed by the expression regulation region of the DNA encoding the inventive protein, was prepared as described below. The luciferase gene of this control reporter plasmid is regulated by the promoter of a thymidine kinase of a herpes simplex virus.

First, a plasmid pRL-TK (Promega) was cleaved by both of HindIII and BglII, subjected to a low melting point agarose electrophoresis (agarose L; Nippon Gene) to recover a DNA fragment (760 bp) containing a TK promoter. Then, a plasmid pGL3 was cleaved by HindIII and BglII, subjected to a BAP treatment followed by a low melting point agarose electrophoresis to recover a BglII-HindIII DNA fragment containing a pGL-derived luciferase gene. About 0.1 μg of the recovered DNA fragment was mixed with about 0.2 μg of the DNA containing the TK promoter described above, and the mixture was reacted with a T4 ligase to prepare a pGL3-TK which was a plasmid comprising the TK promoter-containing DNA as being inserted between the HindIII cleavage site and the BglII cleavage site of the pGL. The DNA of the pGL3-TK thus obtained was cleaved by BanmHI and then subjected to a BAP treatment, followed by a low melting point agarose electrophoresis to recover a DNA fragment which was detected as a single band. This DNA fragment was ligated in the presence of a T4 ligase to a DNA encoding a blasticidin S deaminase gene expression cassette prepared by digesting a plasmid PUCSV-BSD (purchased from FUNAKOSHi) by BamHI, whereby preparing a pGL3-TK-BSD, which is a plasmid comprising the blasticidin S deaminase gene expression cassette as being inserted at the BamHI cleavage site of the pGL3-TK.

About 5×10⁶ cells of 293 cell were cultured in a 10% FBS-supplemented DMEM medium (NISSUI SEIYAKU) at 37° C. in the presence of 5% CO² in a petri dish (Falcon) whose diameter was about 10 cm. On the next day, the cultured cells were dispersed by a trypsin treatment, washed twice with a FBS-free DMEM medium, and then dispersed again in a FBS-free DMEM medium at the cell density of 5×10⁶. 0.4 ml of this cell dispersion was combined with each 3 μg of the plasmids prepared as described above, and the mixture was transferred into an electroporation cuvette, where a transfection was conducted by an electroporation method employing a Gene pulser (BIORAD) under the conditions involving 200V and 950 μF. After the transfection, the culture medium was replaced with a 10% FBS-supplemented DMEM, and then further cultured in a 6-well plate for about 24 hours. Then, the culture medium was removed from the wells, and the cells depositing on the plate wall were washed twice with PBS(−), and then 200 μl per well of a 5-fold diluted PGC 50 (TOYO INK) was added and allowed to stand at room temperature for 30 minutes. 20 μl Aliquots of this cell suspension were dispensed into a opaque plate (Coning Coaster Co., Ltd.), and this plate was mounted on a luminometer LB96P (Berthold, co. ltd) fitted with an enzyme substrate automatic injector, and after dispensing 20 μl of the substrate solution PGL100 (TOYO INK) automatically the luciferase activity of each well was determined.

The results are shown in FIG. 2. The thymidine kinase promoter of the herpes simplex virus (HSV-TK) and the inventive protein-encoding DNA expression regulation region promoter activity were compared, and it was revealed that any of the inventive protein-encoding DNA expression regulation regions containing about 5 kbp, 2.5 kbp and 1 kbp upstream of the transcription initiation point of the gene of the inventive protein (designated as −5 kbp NXF genome, −2.5 kbp NXF genome, and −1 kbp NXF genome in Figure) exhibited a promoter activity which was equal to or higher than that of the HSV-TK promoter (designated as HSV-TK enhancer in Figure) in the 293 cells. It is noteworthy especially that a part critical for the promoter activity identified here was revealed to be present in a region containing about 1 kbp upstream of the transcription initiation point of the gene of the inventive protein.

Example 11 Method for Screening for Altering Transcription Regulation Ability of Inventive Protein Utilizing Expression Regulation Region of DNA Encoding Present Protein

The plasmids into which the expression regulation regions of the DNA encoding the inventive protein containing about 10 kbp, 5 kbp, 2.5 kbp and 1 kbp upstream of the transcription initiation point of the gene of the inventive protein derived from the mouse had been inserted into the upstream of the luciferase gene comprising a TATA minimum promoter prepared in EXAMPLE 10 are transfected into the 293 cells by an electroporation method. After the transfection, the transfected cells are inoculated to a 96-well plate to which (a) a test substance-free culture medium or (b) a test substance-supplemented culture medium had been added. The cells are cultured at 37° C. for about 24 hours, and then examined for the luciferase activity. When the comparison of the measured luciferase activities revealed that the luciferase activity in case (b) is higher than that in case (a), then the relevant test substance is judged to be a substance increasing the expression of the gene of the inventive protein. On the contrary, a lower luciferase activity in case (b) suggests that the relevant test substance is a substance reducing the expression of the gene of the invention. Thus, the substance altering the transcription regulation ability of the inventive protein can be screened for.

INDUSTRIAL APPLICABILITY

Based on the present invention, it becomes possible to provide a bHLH-PAS protein, DNA encoding this protein and the like.

Free Text in Sequence Listing

SEQ ID NO:7

Designed oligonucleotide primer for PCR SEQ ID NO:8

Designed oligonucleotide primer for PCR SEQ ID NO:9

Designed oligonucleotide primer for PCR SEQ ID NO:10

Designed oligonucleotide primer for PCR SEQ ID NO:11

Designed oligonucleotide primer for PCR SEQ ID NO:12

Designed oligonucleotide primer for PCR SEQ ID NO:13

Designed oligonucleotide primer for PCR SEQ ID NO:14

Designed oligonucleotide primer for PCR SEQ ID NO:15

Designed oligonucleotide primer for PCR SEQ ID NO:16

Designed oligonucleotide primer for PCR SEQ ID NO:17

Designed oligonucleotide primer for PCR SEQ ID NO:18

Designed oligonucleotide primer for PCR SEQ ID NO:19

Designed oligonucleotide primer for PCR SEQ ID NO:20

Designed oligonucleotide primer for PCR SEQ ID NO:21

Designed oligonucleotide primer for PCR SEQ ID NO:22

Designed oligonucleotide primer for PCR SEQ ID NO:23

Designed oligonucleotide primer for PCR SEQ ID NO:24

Designed oligonucleotide primer for PCR SEQ ID NO:25

Designed oligonucleotide primer for PCR SEQ ID NO:26

Designed oligonucleotide primer for PCR SEQ ID NO:27

Designed oligonucleotide primer for PCR SEQ ID NO:28

Designed oligonucleotide primer for PCR SEQ ID NO:29

Designed oligonucleotide primer for PCR SEQ ID NO:30

Designed oligonucleotide primer for PCR SEQ ID NO:31

Designed oligonucleotide primer for PCR SEQ ID NO:32

Designed oligonucleotide primer for PCR SEQ ID NO:33

Designed oligonucleotide primer for PCR SEQ ID NO:34

Designed oligonucleotide primer for PCR SEQ ID NO:35

Designed oligonucleotide primer for PCR SEQ ID NO:36

Designed oligonucleotide primer for PCR SEQ ID NO:37

Designed oligonucleotide primer for PCR SEQ ID NO:38

Designed oligonucleotide primer for PCR SEQ ID NO:39

Designed oligonucleotide primer for PCR SEQ ID NO:40

Designed oligonucleotide primer for PCR SEQ ID NO:41

Designed oligonucleotide primer for PCR SEQ ID NO:42

Designed oligonucleotide primer for PCR SEQ ID NO:52

Designed oligonucleotide primer for PCR SEQ ID NO:53

Designed oligonucleotide primer for PCR SEQ ID NO:56

Designed oligonucleotide SEQ ID NO:57 

1. An isolated protein which is any of the following proteins (a) to (e): (a) a protein comprising the amino acid sequence represented by any of SEQ ID NOs: 1 to 3, (b) a protein comprising an amino acid sequence exhibiting an amino acid identity of 90% or more to the amino acid sequence represented by any of SEQ ID NOs: 1 to 3 and also having a transcription regulation ability to regulate expression of drebrin 1, (c) a protein comprising an amino acid sequence encoded by a DNA which hybridizes under a stringent condition that includes washing for 30 minutes at 65° C. in 0.1×SSC with a DNA consisting of the nucleotide sequence represented by the nucleotide numbers 102 to 2507 in the nucleotide sequence represented by SEQ ID NO: 4 and also having a transcription regulation ability to regulate expression of drebrin 1, (d) a protein comprising an amino acid sequence encoded by a DNA which hybridizes under a stringent condition that includes washing for 30 minutes at 65° C. in 0.1×SSC with a DNA consisting of the nucleotide sequence represented by the nucleotide numbers 51 to 2456 in the nucleotide sequence represented by SEQ ID NO: 5 and also having a transcription regulation ability to regulate expression of drebrin 1, and (e) a protein comprising an amino acid sequence encoded by a DNA which hybridizes under a stringent condition that includes washing for 30 minutes at 65° C. in 0.1×SSC with a DNA consisting of the nucleotide sequence represented by the nucleotide numbers 35 to 2440 in the nucleotide sequence represented by SEQ ID NO: 6 and also having a transcription regulation ability to regulate expression of drebrin
 1. 2. An isolated DNA encoding any of the following proteins (a) to (e): (a) a protein comprising the amino acid sequence represented by any of SEQ ID NOs: 1 to 3, (b) a protein comprising an amino acid sequence exhibiting an amino acid identity of 90% or more to the amino acid sequence represented by any of SEQ ID NOs: 1 to 3 and also having a transcription regulation ability to regulate expression of drebrin 1, (c) a protein comprising an amino acid sequence encoded by a DNA which hybridizes under a stringent condition that includes washing for 30 minutes at 65° C. in 0.1×SSC with a DNA consisting of the nucleotide sequence represented by the nucleotide numbers 102 to 2507 in the nucleotide sequence represented by SEQ ID NO: 4 and also having a transcription regulation ability to regulate expression of drebrin 1, (d) a protein comprising an amino acid sequence encoded by a DNA which hybridizes under a stringent condition that includes washing for 30 minutes at 65° C. in 0.1×SSC with a DNA consisting of the nucleotide sequence represented by the nucleotide numbers 51 to 2456 in the nucleotide sequence represented by SEQ ID NO: 5 and also having a transcription regulation ability to regulate expression of drebrin 1, and (e) a protein comprising an amino acid sequence encoded by a DNA which hybridizes under a stringent condition that includes washing for 30 minutes at 65° C. in 0.1×SSC with a DNA consisting of the nucleotide sequence represented by the nucleotide numbers 35 to 2440 in the nucleotide sequence represented by SEQ ID NO: 6 and also having a transcription regulation ability to regulate expression of drebrin
 1. 3. An isolated DNA comprising any of the following nucleotide sequences (a) to (d): (a) the nucleotide sequence represented by the nucleotide numbers 102 to 2507 in the nucleotide sequence represented by SEQ ID NO: 4, (b) the nucleotide sequence represented by the nucleotide numbers 51 to 2456 in the nucleotide sequence represented by SEQ ID NO: 5, (c) the nucleotide sequence represented by the nucleotide numbers 35 to 2440 in the nucleotide sequence represented by SEQ ID NO: 6, and (d) the nucleotide sequence represented by the nucleotide numbers 1419 to 6164 in the nucleotide sequence represented by SEQ ID NO:
 54. 4. A vector containing the DNA according to claim 2 or
 3. 5. A vector containing a DNA being formed by operably connecting a promoter to the upstream of the DNA according to claim 2 or
 3. 6. A method for producing a vector comprising integrating the DNA according to claim 2 or 3 into a vector which can replicate itself in a host cell.
 7. A transformed cell formed by introducing the DNA according to claim 2 or 3 into a host cell.
 8. A transformed cell according to claim 7 wherein the host cell is an animal cell.
 9. A transformed cell according to claim 7 wherein the host cell is a E. coli or yeast.
 10. A method for producing a transformed cell comprising introducing the DNA according to claim 2 or 3 into a host cell.
 11. A method for producing any of the following proteins (a) to (e) comprising culturing a transformed cell formed by introducing the DNA encoding said protein and recovering said protein from the culture: (a) a protein comprising the amino acid sequence represented by any of SEQ ID NOs: 1 to 3, (b) a protein comprising an amino acid sequence exhibiting an amino acid identity of 90% or more to the amino acid sequence represented by any of SEQ ID NOs: 1 to 3 and also having a transcription regulation ability to regulate expression of drebrin 1, (c) a protein comprising an amino acid sequence encoded by a DNA which hybridizes under a stringent condition that includes washing for 30 minutes at 65° C. in 0.1×SSC with a DNA consisting of the nucleotide sequence represented by the nucleotide numbers 102 to 2507 in the nucleotide sequence represented by SEQ ID NO: 4 and also having a transcription regulation ability to regulate expression of drebrin 1, (d) a protein comprising an amino acid sequence encoded by a DNA which hybridizes under a stringent condition that includes washing for 30 minutes at 65° C. in 0.1×SSC with a DNA consisting of the nucleotide sequence represented by the nucleotide numbers 51 to 2456 in the nucleotide sequence represented by SEQ ID NO: 5 and also having a transcription regulation ability to regulate expression of drebrin 1, and (e) a protein comprising an amino acid sequence encoded by a DNA which hybridizes under a stringent condition that includes washing for 30 minutes at 65° C. in 0.1×SSC with a DNA consisting of the nucleotide sequence represented by the nucleotide numbers 35 to 2440 in the nucleotide sequence represented by SEQ ID NO: 6 and also having a transcription regulation ability to regulate expression of drebrin 1, into a host cell.
 12. A method for screening for a substance which binds to any of the following proteins (a) to (e) comprising: (1) a step for bringing said protein into contact with a test sample; and (2) a step for selecting a substance which binds to said protein; wherein said protein is selected from the group consisting of: (a) a protein comprising the amino acid sequence represented by any of SEQ ID NOs: 1 to 3, (b) a protein comprising an amino acid sequence exhibiting an amino acid identity of 90% or more to the amino acid sequence represented by any of SEQ ID NOs: 1 to 3 and also having a transcription regulation ability to regulate expression of drebrin 1, (c) a protein comprising an amino acid sequence encoded by a DNA which hybridizes under a stringent condition that includes washing for 30 minutes at 65° C. in 0.1×SSC with a DNA consisting of the nucleotide sequence represented by the nucleotide numbers 102 to 2507 in the nucleotide sequence represented by SEQ ID NO: 4 and also having a transcription regulation ability to regulate expression of drebrin 1, (d) a protein comprising an amino acid sequence encoded by a DNA which hybridizes under a stringent condition that includes washing for 30 minutes at 65° C. in 0.1×SSC with a DNA consisting of the nucleotide sequence represented by the nucleotide numbers 51 to 2456 in the nucleotide sequence represented by SEQ ID NO: 5 and also having a transcription regulation ability to regulate expression of drebrin 1, and (e) a protein comprising an amino acid sequence encoded by a DNA which hybridizes under a stringent condition that includes washing for 30 minutes at 65° C. in 0.1×SSC with a DNA consisting of the nucleotide sequence represented by the nucleotide numbers 35 to 2440 in the nucleotide sequence represented by SEQ ID NO: 6 and also having a transcription regulation ability to regulate expression of drebrin
 1. 13. A method for measuring a transcription regulation ability of any of the following proteins (a) to (e) comprising: a step for measuring the expression level of a reporter gene in a first transformed cell, wherein said first transformed cell is formed by introducing a gene i) and gene ii) into a host cell and in a second transformed cell, wherein said second transformed cell is formed by introducing a gene iii) and gene ii) and then comparing the measured expression levels from said first transformed cell and said second transformed cell; wherein: gene i) is a chimeric gene formed by connecting, to a downstream of a promoter which is capable of functioning in a host cell, a DNA encoding a fusion protein of a DNA binding region of a transcription regulatory factor which is capable of functioning in the host cell and said protein; gene ii) is a reporter gene formed by connecting a DNA encoding a reporter protein to a downstream of a promoter containing a DNA to which the DNA binding region described in i) can be bound and a minimum promoter which is capable of functioning in a host cell; gene iii) is a gene formed by connecting, to the downstream of the promoter described in i), a DNA encoding the DNA binding region described in i); and wherein said protein is selected from the group consisting of: (a) a protein comprising the amino acid sequence represented by any of SEQ ID NOs: 1 to 3, (b) a protein comprising an amino acid sequence exhibiting an amino acid identity of 90% or more to the amino acid sequence represented by any of SEQ ID NOs: 1 to 3 and also having a transcription regulation ability to regulate expression of drebrin 1, (c) a protein comprising an amino acid sequence encoded by a DNA which hybridizes under a stringent condition that includes washing for 30 minutes at 65° C. in 0.1×SSC with a DNA consisting of the nucleotide sequence represented by the nucleotide numbers 102 to 2507 in the nucleotide sequence represented by SEQ ID No. 4 and also having a transcription regulation ability to regulate expression of drebrin 1, (d) a protein comprising an amino acid sequence encoded by a DNA which hybridizes under a stringent condition that includes washing for 30 minutes at 65° C. in 0.1×SSC with a DNA consisting of the nucleotide sequence represented by the nucleotide numbers 51 to 2456 in the nucleotide sequence represented by SEQ ID NO: 5 and also having a transcription regulation ability to regulate expression of drebrin 1, and (e) a protein comprising an amino acid sequence encoded by a DNA which hybridizes under a stringent condition that includes washing for 30 minutes at 65° C. in 0.1×SSC with a DNA consisting of the nucleotide sequence represented by the nucleotide numbers 35 to 2440 the nucleotide sequence represented by SEQ ID NO: 6 and also having a transcription regulation ability to regulate expression of drebrin
 1. 14. A method for screening for a substance which alters the transcription regulation ability of any of the following proteins (a) to (e) comprising: (1) a step for bringing a transformed cell formed by introducing: i) a chimeric gene formed by connecting, to a downstream of a promoter which is capable of functioning in a host cell, a DNA encoding a fusion protein of a DNA binding region of a transcription regulatory factor which is capable of functioning in the host cell and said protein, and ii) a reporter gene formed by connecting a DNA encoding a reporter protein to a downstream of a promoter containing a DNA to which the DNA binding region described in i) can be bound and a minimum promoter which is capable of functioning in a host cell, into a host cell into contact with a test substance and then measuring the expression level of said reporter gene in the presence of the test substance, and (2) a step for selecting a test substance which results in a expression level of said reporter gene, as measured in the step (a), which is different from the expression level of said reporter gene in the absence of the test substance; wherein said protein is selected from the group consisting of: (a) a protein comprising the amino acid sequence represented by any of SEQ ID NOs: 1 to 3, (b) a protein comprising an amino acid sequence exhibiting an amino acid identity of 90% or more to the amino acid sequence represented by any of SEQ ID NOs: 1 to 3 and also having a transcription regulation ability to regulate expression of drebrin 1, (c) a protein comprising an amino acid sequence encoded by a DNA which hybridizes under a stringent condition that includes washing for 30 minutes at 65° C. in 0.1×SSC with a DNA consisting of the nucleotide sequence represented by the nucleotide numbers 102 to 2507 in the nucleotide sequence represented by SEQ ID NO: 4 and also having a transcription regulation ability to regulate expression of drebrin 1, (d) a protein comprising an amino acid sequence encoded by a DNA which hybridizes under a stringent condition that includes washing for 30 minutes at 65° C. in 0.1×SSC with a DNA consisting of the nucleotide sequence represented by the nucleotide numbers 51 to 2456 in the nucleotide sequence represented by SEQ ID NO: 5 and also having a transcription regulation ability to regulate expression of drebrin 1, and (e) a protein comprising an amino acid sequence encoded by a DNA which hybridizes under a stringent condition that includes washing for 30 minutes at 65° C. in 0.1×SSC with a DNA consisting of the nucleotide sequence represented by the nucleotide numbers 35 to 2440 in the nucleotide sequence represented by SEQ ID NO: 6 and also having a transcription regulation ability to regulate expression of drebrin
 1. 15. A method for screening for a substance which alters the intracellular expression level of any of the following proteins (a) to (e) comprising: (1) a step for bringing a transformed cell formed by introducing into a host cell a reporter gene operably ligated to the expression regulation region of a DNA encoding said protein into contact with a test substance and then measuring the expression level of said reporter gene in the presence of the test substance, and (2) a step for selecting a test substance which results in a expression level of said reporter gene, as measured in the step (1), which is different from the expression level of said reporter gene in the absence of the test substance; wherein said protein is selected from the group consisting of: (a) a protein comprising the amino acid sequence represented by any of SEQ ID NOs: 1 to 3, (b) a protein comprising an amino acid sequence exhibiting an amino acid identity of 90% or more to the amino acid sequence represented by any of SEQ ID NOs: 1 to 3 and also having a transcription regulation ability to regulate expression of drebrin 1, (c) a protein comprising an amino acid sequence encoded by a DNA which hybridizes under a stringent condition that includes washing for 30 minutes at 65° C. in 0.1×SSC with a DNA consisting of the nucleotide sequence represented by the nucleotide numbers 102 to 2507 in the nucleotide sequence represented by SEQ ID NO: 4 and also having a transcription regulation ability to regulate expression of drebrin 1, (d) a protein comprising an amino acid sequence encoded by a DNA which hybridizes under a stringent condition that includes washing for 30 minutes at 65° C. in 0.1×SSC with a DNA consisting of the nucleotide sequence represented by the nucleotide numbers 51 to 2456 in the nucleotide sequence represented by SEQ ID NO: 5 and also having a transcription regulation ability to regulate expression of drebrin 1, and (e) a protein comprising an amino acid sequence encoded by a DNA which hybridizes under a stringent condition that includes washing for 30 minutes at 65° C. in 0.1×SSC with a DNA consisting of the nucleotide sequence represented by the nucleotide numbers 35 to 2440 in the nucleotide sequence represented by SEQ ID NO: 6 and also having a transcription regulation ability to regulate expression of drebrin
 1. 16. A method for analyzing a genotype of a gene encoding any of the following proteins (a) to (e) comprising a step for investigating whether a nucleotide sequence encoding said protein, in a nucleic acid in a test sample, contains a nucleotide sequence encoding an amino acid sequence which is different from the amino acid sequence of a standard protein or not; wherein said protein is selected from the group consisting of: (a) a protein comprising the amino acid sequence represented by any of SEQ ID NOs: 1 to 3, (b) a protein comprising an amino acid sequence exhibiting an amino acid identity of 90% or more to the amino acid sequence represented by any of SEQ ID NOs: 1 to 3 and also having a transcription regulation ability to regulate expression of drebrin 1, (c) a protein comprising an amino acid sequence encoded by a DNA which hybridizes under a stringent condition that includes washing for 30 minutes at 65° C. in 0.1×SSC with a DNA consisting of the nucleotide sequence represented by the nucleotide numbers 102 to 2507 in the nucleotide sequence represented by SEQ ID NO: 4 and also having a transcription regulation ability to regulate expression of drebrin 1, (d) a protein comprising an amino acid sequence encoded by a DNA which hybridizes under a stringent condition that includes washing for 30 minutes at 65° C. in 0.1×SSC with a DNA consisting of the nucleotide sequence represented by the nucleotide numbers 51 to 2456 in the nucleotide sequence represented by SEQ ID NO: 5 and also having a transcription regulation ability to regulate expression of drebrin 1, and (e) a protein comprising an amino acid sequence encoded by a DNA which hybridizes under a stringent condition that includes washing for 30 minutes at 65° C. in 0.1×SSC with a DNA consisting of the nucleotide sequence represented by the nucleotide numbers 35 to 2440 in the nucleotide sequence represented by SEQ ID NO: 6 and also having a transcription regulation ability to regulate expression of drebrin
 1. 17. A method according to claim 16 wherein the step for investigating whether a nucleotide sequence encoding the amino acid sequence which is different from the amino acid sequence of a standard protein is contained or not comprises a step for amplifying a DNA encoding any of the proteins (a) to (e) using the nucleic acid in the test sample as a template and then determining the nucleotide sequence of the amplified DNA.
 18. A method according to claim 16 wherein the step for investigating whether a nucleotide sequence encoding the amino acid sequence which is different from the amino acid sequence of a standard protein is contained or not comprises a step for amplifying a DNA encoding the amino acid sequence of any of the proteins (a) to (e) using the nucleic acid in the test sample as a template and then subjecting the amplified DNA to an electrophoresis to measure the mobility.
 19. A method according to claim 16 wherein the step for investigating whether a nucleotide sequence encoding the amino acid sequence which is different from the amino acid sequence of a standard protein is contained or not comprises a step for investigating the pattern of a hybridization under a stringent condition between the nucleic acid of a test sample or an amplification product of said nucleic acid and a polynucleotide consisting of 10 to 5000 nucleotides capable of hybridizing under a stringent condition with a polynucleotide consisting of the nucleotide sequence represented by SEQ ID NO: 4, 5, 6 or 54 or the nucleotide sequence complementary to said nucleotide sequence wherein said stringent condition includes washing for 30 minutes at 65° C. in 0.1×SSC.
 20. A method according to any of claims 16 to 19 wherein the amino acid sequence of the standard protein is the amino acid sequence represented by SEQ ID NO: 1, 2 or
 3. 21. A method for promoting the expression of a drebrin 1 in a mammalian cell comprising a step for providing the mammalian cell with the DNA according to claim 2 or 3 in a position enabling the expression of said DNA in said cell. 